Feverish conditions of unknown etiology. Increased body temperature in children with developmental disabilities: available methods and medications

Fever of unknown origin - main symptoms:

Headache
Mood swings
Weakness
Lower back pain
Joint pain
Dizziness
Fever
Nausea
Cardiopalmus
Loss of appetite
Vomit
Chills
Lack of air
Heartache
Muscle pain
Increased sweating
Pale skin
Extreme thirst
Feeling broken
Abnormal stool

Fever of unknown origin and syn. LNG is a clinical case in which elevated body temperature is the leading or only clinical sign. This condition is indicated when the values persist for 3 weeks (in children - longer than 8 days) or more.

Possible reasons may be oncological processes, systemic and hereditary pathologies, drug overdose, .

Clinical manifestations often limited to an increase in temperature to 38 degrees. This condition may be accompanied by chills, increased sweating, attacks of suffocation and pain various localizations.

Object diagnostic search the root cause appears, so the patient is required to undergo wide range laboratory and instrumental procedures. Primary diagnostic measures are necessary.

The treatment algorithm is selected individually. If the patient's condition is stable, treatment is not required at all. In severe cases, a trial regimen is used, depending on the suspected pathological provocateur.

According to the International Classification of Diseases, Tenth Revision, fever of unknown origin has its own code. The ICD-10 code is R50.

Causes of the disease

A febrile state that lasts no more than 1 week indicates an infection. It is assumed that prolonged fever is associated with the course of some serious pathology.

Fever of unknown origin in children or adults may be the result of an overdose of drugs:

antimicrobial agents;
antibiotics;
sulfonamides;
nitrofurans;
anti-inflammatory drugs;
, which are prescribed for gastrointestinal diseases;
cardiovascular medications;
cytostatics;
antihistamines;
iodine preparations;
substances that affect the central nervous system.

The medicinal nature is not confirmed in cases where temperature values remain high within 1 week after discontinuation of the medication.

Causes of fever of unknown origin

Classification

Based on the nature of the course, fever of unknown origin occurs:

classical - against the background of pathologies known to science;
nosocomial - occurs in persons who are in the intensive care unit for more than 2 days;
neutropenic - there is a decrease in the number of neutrophils in the blood;
HIV-associated.

According to the level of temperature increase in LNG there are:

subfebrile - varies from 37.2 to 37.9 degrees;
febrile - 38–38.9 degrees;
pyretic - from 39 to 40.9;
hyperpyretic - above 41 degrees.

Based on the type of changes in values, the following types of hyperthermia are distinguished:

constant - daily fluctuations do not exceed 1 degree;
weakening - variability throughout the day is 1–2 degrees;
intermittent - alternation occurs normal condition with pathological, duration is 1–3 days;
hectic - marked sharp jumps temperature indicators;
wavy - the thermometer readings gradually decrease, after which they increase again;
perverted - indicators are higher in the mornings than in the evenings;
incorrect - has no patterns.

Duration of fever of unknown origin can be:

acute - persists no longer than 15 days;
subacute - the interval is from 16 to 45 days;
chronic - more than 1.5 months.

Symptoms of the disease

The main, and in some cases the only, symptom of fever of unknown origin is an increase in body temperature.

The peculiarity of this condition is that the pathology over a fairly long period of time can be completely asymptomatic or with erased symptoms.

Main additional manifestations:

muscle and joint pain;
dizziness;
feeling of lack of air;
increased heart rate;
chills;
increased sweating;
pain in the heart, lower back or head;
lack of appetite;
stool disorder;
nausea and vomiting;
weakness and weakness;
frequent mood changes;
strong thirst;
drowsiness;
pale skin;
decreased performance.

External signs occur in both adults and children. However, in the second category of patients, the degree of severity accompanying symptoms could be much higher.

Diagnostics

Diagnosis of fever of unknown origin

To identify the cause of fever of unknown origin, a comprehensive examination of patients is required. Before carrying out laboratory and instrumental studies, primary diagnostic measures are required, carried out by a pulmonologist.

The first step in establishing a correct diagnosis includes:

studying medical history - to look for chronic diseases;
collection and analysis of life history;
a thorough physical examination of the patient;
listening to a person using a phonendoscope;
measurement of temperature values;
detailed survey of the patient regarding the first time of occurrence of the main symptom and the severity of associated symptoms external manifestations and hyperthermia.

Laboratory research:

general clinical and biochemical blood tests;
microscopic examination of feces;
general urine analysis;
bacterial seeding of all human biological fluids;
hormonal and immunological tests;
bacterioscopy;
serological reactions;
PCR tests;
Mantoux test;
tests for AIDS and.

Instrumental diagnostics fever of unknown origin involves the following procedures:

radiography;
CT and MRI;
skeletal system scan;
ultrasonography;
ECG and EchoCG;
colonoscopy;
puncture and biopsy;
scintigraphy;
densitometry;
EFGDS;
MSCT.

Densitometry

Consultation with specialists from various areas medicine, for example, gastroenterology, neurology, gynecology, pediatrics, endocrinology, etc. Depending on which doctor the patient goes to, they may be prescribed additional procedures diagnosing.

Differential diagnosis is divided into the following main subgroups:

infectious and viral diseases;
oncology;
autoimmune diseases;
systemic disorders;
other pathologies.

Treatment of the disease

When a person’s condition is stable, experts recommend refraining from treating fever of unknown origin in children and adults.

In all other situations, trial therapy is performed, the essence of which will differ depending on the alleged provocateur:

for tuberculosis, anti-tuberculosis substances are prescribed;
infections are treated with antibiotics;
viral diseases are eliminated with the help of immunostimulants;
autoimmune processes are a direct indication for the use of glucocorticoids;
for gastrointestinal diseases, in addition to medications, diet therapy is prescribed;
when malignant tumors are detected, they are indicated surgical intervention, chemotherapy and radiotherapy.

If drug-induced LNG is suspected, it is necessary to discontinue the medications the patient is taking.

As for treatment with folk remedies, it must be agreed with the attending physician - if this is not done, the possibility of worsening the problem cannot be ruled out, and the risk of complications increases.

Prevention and prognosis

To reduce the likelihood of developing a pathological condition, it is necessary to adhere to preventive recommendations aimed at preventing the occurrence of a possible provoking disease.

Prevention:

conducting healthy image life;
complete and balanced nutrition;
avoiding the influence of stressful situations;
preventing any injuries;
constant strengthening of the immune system;
taking medications in accordance with the recommendations of the clinician who prescribed them;
early diagnosis and full treatment any pathologies;
regular completion of preventive examination V medical institution with visits to all specialists.

Fever of unknown origin has an ambiguous prognosis, which depends on the underlying cause. A complete lack of therapy is fraught with the development of complications of one or another underlying disease, which often ends in death.

Fever of unknown origin - symptoms and treatment, photos and videos

What to do?

If you think that you have Fever of unknown origin and the symptoms characteristic of this disease, then doctors can help you: pulmonologist, therapist, pediatrician.

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If, against the background of the absence of other painful symptoms the temperature suddenly rises and persists for a long period, there is a suspicion that this is fever of unknown origin (FOU). It can occur in both adults and children with other diseases.

Causes of fever

In fact, fever is nothing more than a protective function of the body, which is “involved” in the fight against active bacteria or other pathogens. In simple terms, due to the increase in temperature, they are destroyed. Related to this is the recommendation not to lower the temperature with pills if it does not exceed 38 degrees, in order to allow the body to cope with the problem on its own.
The characteristic causes of LNG are severe systemic infectious diseases:

tuberculosis;
salmonella infection;
brucellosis;
borelliosis;
tularemia;
syphilis (see also -);
leptospirosis;
malaria;
toxoplasma;
AIDS;
sepsis.

Among the localized diseases that cause fever are:

blood vessel thrombi;
abscess;
hepatitis;
damage to the genitourinary system;
osteomyelitis;
dental infections.

Symptoms of a febrile state

The main sign of this disease is elevated temperature body, which can last up to 14 days. Along with this, symptoms characteristic of patients of any age appear:

lack of appetite;
weakness, fatigue;
increased sweating;
chills;

These symptoms are general in nature, they are common to most other diseases. Therefore, it is necessary to pay attention to such nuances as the presence of chronic diseases, reactions to medications, and contact with animals.

Symptoms "pink" And "pale" fevers differ in clinical features. At the first type of fever in an adult or child, the skin is of normal color, slightly moist and warm - this condition is considered not very dangerous and passes easily. If the skin is dry, vomiting, shortness of breath and diarrhea appear, the alarm should be sounded to prevent excessive dehydration.

"Pale" fever is accompanied by marbled pallor and dry skin, blue lips. The extremities of the arms and legs also become cold, and heartbeat irregularities occur. Such signs indicate a severe form of the disease and require immediate medical intervention.

When the body does not respond to antipyretic drugs and the body temperature goes off scale, dysfunction of important organs may occur. Scientifically, this condition is called hyperthermic syndrome.

With “pale” fever, emergency comprehensive medical care is necessary, otherwise irreversible processes may begin, which sometimes lead to death.

If a newborn has a fever of more than 38 degrees, or a child over one year old has a fever of 38.6 or higher, you should immediately consult a doctor. The same must be done if an adult has a fever of up to 40 degrees.

Classification of the disease

During the study, medical researchers identified two main types of LNG: infectious And non-infectious.

The first type is characterized by the following factors:

immune (allergies, diseases connective tissue);
central (problems with the central nervous system);
psychogenic (neurotic and psychophysical disorders);
reflex (feeling of severe pain);
endocrine (metabolic disorders);
resorption (incision, bruise, tissue necrosis);
medicinal;
hereditary.

A febrile state with an increase in temperature of non-infectious etymology appears as a result of central or peripheral exposure to leukocyte breakdown products (endogenous pyrogens).

Fever is also classified according to temperature indicators:

subfebrile – from 37.2 to 38 degrees;
febrile low – from 38.1 to 39 degrees;
febrile high – from 39.1 to 40 degrees;
excessive - more than 40 degrees.

By duration There are different types of fever:

ephemeral – from several hours to 3 days;
acute – up to 14-15 days;
subacute – up to 44-45 days;
chronic – 45 or more days.

Survey methods

The attending physician sets himself the task of determining which types of bacteria or viruses turned out to be the causative agent of fever of unknown origin. Premature newborns up to six months of age, as well as adults with a weakened body due to a chronic disease or other reasons listed above, are especially susceptible to their effects.

To clarify the diagnosis, a series of laboratory research:

general blood test to determine the content of platelets, leukocytes, ESR;
urine analysis for the content of leukocytes;
blood chemistry;
bacterial cultures of blood, urine, feces, mucus from the larynx from cough.

In addition, in some cases, bacterioscopy to exclude suspicion of malaria. Also, sometimes the patient is offered to undergo a comprehensive examination for tuberculosis, AIDS and other infectious diseases.

Fever of unknown origin is so difficult to diagnose that it is impossible to do without examinations using special medical equipment. The patient undergoes:

tomography;
skeletal scan;
X-ray;
echocardiography;
colonoscopy;
bone marrow puncture;
biopsy of liver, muscle tissue and lymph nodes.

The range of all diagnostic methods and tools is quite wide; on their basis, the doctor develops a specific treatment algorithm for each patient. It takes into account the presence of obvious symptoms:

joint pain;
change in hemoglobin level;
inflammation of the lymph nodes;
the appearance of pain in the area of internal organs.

In this case, the doctor has the opportunity to move more purposefully towards establishing an accurate diagnosis.

Features of treatment

Despite the fact that fever of unknown origin poses a danger not only to health, but also to human life, one should not rush to take medications. Although some doctors prescribe antibiotics and carticosteroids long before determining the final diagnosis, citing the motivation to alleviate the patient’s physical condition as soon as possible. However, this approach does not allow making the right decision for more effective treatment. If the body is under the influence of antibiotics, it becomes more difficult in the laboratory to find the true cause of the fever.

According to most doctors, it is necessary to conduct further examination of the patient using only symptomatic therapy. It is carried out without prescribing potent drugs that blur the clinical picture.

If the patient continues high fever, he is advised to drink plenty of fluids. The diet excludes foods that cause allergies.

If infectious manifestations are suspected, he is placed in an isolated ward of a medical institution.

Treatment medications carried out after detection of the disease that provoked the fever. If the etiology (cause of the disease) of fever has not been established after all diagnostic procedures, the use of antipyretics and antibiotics is allowed.

under 2 years of age with a temperature above 38 degrees;
at any age after 2 years – over 40 degrees;
who have febrile seizures;
who have central nervous system diseases;
with dysfunctions of the circulatory system;
with obstructive syndrome;
with hereditary diseases.

Which doctor should I contact?

If an adult exhibits obvious symptoms LNG, he should contact infectious disease specialist. Although most often people turn to therapist. But if he notices the slightest suspicion of fever, he will certainly refer you to an infectious disease specialist.

Many parents are interested in which doctors should be contacted at the first symptoms of the disease in question in children. First of all, to pediatrician. After the preliminary stage of examination, the doctor refers the small patient to one or more specialized specialists: cardiologist, infectious disease specialist, allergist, endocrinologist, virologist, nephrologist, otolaryngologist, neurologist.

Each of these doctors takes part in studying the patient's condition. If it is possible to determine the development of a concomitant disease, for example, associated with an allergic reaction to food or medications, an allergist will help.

Drug treatment

For each patient, the doctor develops an individual medication program. The specialist takes into account the condition against which the disease develops, determines the degree of hyperthermia, classifies the type of fever and prescribes medications.

According to doctors, medications are not assigned at "pink" fever with an unburdened background (maximum temperature 39 degrees). If the patient does not have serious illnesses, condition and behavior are adequate, it is recommended to limit yourself to drinking plenty of fluids and using body cooling methods.

If the patient is at risk and has "pale" fever, he is assigned Paracetamol or Ibuprofen . These drugs meet the criteria for therapeutic safety and effectiveness.

According to WHO, Aspirin refers to antipyretics that are not used to treat children under 12 years of age. If the patient cannot tolerate Paracetamol and Ibuprofen, he is prescribed Metamizole .

Doctors recommend taking Ibuprofen and Paracetamol at the same time, according to a scheme developed individually for each patient. When used in combination, the dosage of such medications is minimal, but this gives a significantly greater effect.

There is a drug Ibuklin , one tablet of which contains the low-dose components of paracetamol (125 mg) and ibuprofen (100 mg). This drug has a rapid and prolonged effect. Children should take:

from 3 to 6 years (body weight 14-21 kg) 3 tablets;
from 6 to 12 years (22-41 kg) 5-6 tablets every 4 hours;
over 12 years old – 1 tablet.

Adults are prescribed dosage depending on age, body weight and physical condition body (presence of other diseases).
Antibiotics selected by the doctor in accordance with the test results:

antipyretics (Paracetamol, Indomethacin, Naproxen);
Stage 1 of taking antibiotics (Gentamicin, Ceftazidime, Azlin);
Stage 2 – appointment of more strong antibiotics(Cefazolin, Amphotericin, Fluconazole).

Folk recipes

On this hour ethnoscience presents a huge selection of funds for every occasion. Let's look at some recipes that help alleviate the condition of fever of unknown origin.

Lesser periwinkle decoction: Pour 1 tablespoon of dry leaves into a vessel with a glass of water and boil for 20-25 minutes. After an hour, strain and the broth is ready. You should drink the entire volume per day in 3 doses.

Tench fish. Dried fish gall bladder must be ground into powder. Take 1 bottle per day with water.

willow bark. Pour 1 teaspoon of bark into the brewing container, after crushing it, pour in 300 ml of water. Boil, reducing heat to low, until about 50 ml has evaporated. It should be taken on an empty stomach; you can add a little honey to the decoction. You must continue drinking until complete recovery.

LNG is one of the diseases whose treatment is very difficult due to the difficulty of determining the causes of its occurrence, so you should not use folk remedies without the permission of the attending physician.

Preventive measures for children and adults

To prevent a feverish state, basic health care is necessary in the form of regular medical examination. Thus, it is possible to guarantee timely detection all kinds of pathologies. The earlier the diagnosis of a particular disease is established, the more favorable the treatment outcome will be. After all, it is a complication of an advanced disease that most often causes fever of unknown origin.

There are rules that, if followed, will reduce the likelihood of LNG in children to zero:

do not contact with infectious patients;
receive a complete balanced diet;
physical activity;
vaccination;
maintaining personal hygiene.

All these recommendations are also acceptable for adults with a small addition:

exclude random connections sexual in nature;
use in intimate life barrier contraception methods;
When staying abroad, do not eat unknown foods.

Infectious disease specialist about LNG (video)

In this video, an infectious disease doctor will talk about the causes of fever, its types, methods of diagnosis and treatment from his point of view.

An important point is heredity and the body’s predisposition to certain diseases. After a thorough comprehensive examination, the doctor will be able to make the correct diagnosis and prescribe an effective therapeutic course to eliminate the causes of fever.

Next article.

In clinical practice, situations often arise when, against the background good health the patient suddenly has an increase in natural temperature body (the indicator often exceeds 38°C). Moreover, such prolonged hyperthermia may be the only symptom that indicates some disturbance in the body. But numerous diagnostic studies do not allow us to determine a specific pathological process. In this case, the attending physician diagnoses the patient with fever unknown etiology» and gives a referral for a more detailed health examination.

Fever lasting more than 1 week is most likely caused by some serious illness. As practice shows, hyperthermia in approximately 90% of cases is an indicator of the occurrence of an infectious process in the body, the presence of a malignant neoplasm, or damage to connective tissues of a systemic nature. In rare cases, prolonged fever indicates atypical form the course of common diseases that the patient has encountered more than once in his life.

There are the following causes of fever of unknown origin:

Other causes of hyperthermia have been identified. For example, medicinal or medicinal. Drug fever is a persistent increase in temperature caused by hypersensitivity to a number of certain drugs, which are most often used more than once. These may include painkillers, diuretics, some antibiotics, antihistamines and sedatives.

Classification of fever of unknown origin

In medicine, several types of fever have been studied and identified depending on the nature of changes in body temperature over time:

Permanent (stable type). The temperature is high (about 39°C) and remains stable for several days. Fluctuations during the day do not exceed 1°C (pneumonia).
Relaxing fever. Daily fluctuations are 1-2°C. The temperature does not drop to the usual level (diseases with purulent tissue damage).
Intermittent fever. Hyperthermia alternates with natural healthy condition patient (malaria).
Wavy. The increase in temperature occurs gradually, followed by the same systematic decrease to a low-grade level (brucellosis, lymphogranulomatosis).
Wrong fever. During the course of hyperthermia there is no pattern in daily change indicator (flu, cancer, rheumatism).
Return type. Elevated temperature (up to 40°C) alternates with low-grade fever (typhoid).
Perverted fever. The morning temperature is higher than in the afternoon (diseases of viral etiology, sepsis).

Based on the duration of the disease, acute (less than 15 days), subacute (15-45 days) or chronic fever (over 45 days) are distinguished.

Symptoms of the disease

Usually the only and pronounced symptom prolonged fever is an elevated body temperature. But against the background of hyperthermia, other signs of an unknown disease may develop:

increased work of sweat glands;
suffocation;
chills;
pain in the heart area;
dyspnea.

Diagnosis of fever of unknown origin

Prolonged fever of unknown origin requires the use of standard and specific research methods. Making a diagnosis is considered a painstaking and time-consuming task. First of all, the patient needs to see a therapist at the clinic. He will establish the duration of hyperthermia, the characteristics of its changes (fluctuations) during the day. The specialist will also determine what diagnostic methods the examination will consist of.

Standard diagnostic procedures for prolonged fever syndrome:

Blood and urine tests (general), detailed coagulogram.
Biochemical study of blood from the ulnar vein. Clinical data will be obtained on the amount of sugar, sialic acids, total protein, AST, CRP in the biomaterial.
The simplest diagnostic method is the aspirin test. The patient is asked to take an antipyretic tablet (paracetamol, aspirin). After 40 minutes, observe whether the temperature has decreased. If there is a change of even one degree, it means that an inflammatory process is occurring in the body.
Mantoux test.
Three-hour thermometry (measurement of temperature indicators).
X-ray of the lungs. Used to determine such complex diseases as sarcoidosis, tuberculosis, lymphoma.
Ultrasound of organs located in abdominal cavity and pelvic area. Used in cases of suspected obstructive kidney disease, neoplasms in organs, or pathologies of the biliary system.
ECG and EchoCG (it is advisable to perform if there is a possibility of atrial myxoma, fibrosis of the heart valves, etc.).
CT or MRI of the brain.

If the above tests do not reveal specific disease or their results are controversial, then a series of additional studies are prescribed:

Studying information about possible hereditary diseases.
Obtaining information about the patient's existing allergic reactions. Especially those that arise from the use of medications.
Study of tissues and mucous membranes of the gastrointestinal tract for tumors and inflammatory processes. For this, endoscopy, radiation diagnostics or biopsy are used.
Serological studies blood, which are prescribed for suspected hepatitis, HIV infection, cytomegalovirus, amoebiasis, syphilis, brucellosis, infections caused by the Epstein-Barr virus.
Microbiological tests various types patient’s biomaterial – urine, blood, nasopharyngeal secretions. In some cases, a blood test for intrauterine infections is necessary.
Microscopic analysis of a thick drop of blood (to exclude the malaria virus).
Collection and analysis of bone marrow puncture.
Study of blood mass for the so-called antinuclear factor (exclusion of lupus).

Differential diagnosis of fevers is divided into 4 main subgroups:

association of common infectious diseases.
oncological subgroup.
autoimmune pathologies.
other diseases.

During the differentiation procedure, the specialist must pay attention not only to those symptoms that bother the person in this moment time, but also to those that he encountered earlier.

It is necessary to take into account the conducted surgical operations, chronic diseases and psycho-emotional characteristics of each individual patient. If a man long time takes any medications, you must inform the diagnostician about this.

Prevention of fever of unknown origin

Prevention, first of all, consists of quick and correct diagnosis diseases that cause a persistent increase in temperature over a long period of time. At the same time, you cannot self-medicate, choose even the simplest medications yourself.

A mandatory preventive measure is the constant maintenance high level immune defense. If one of the family members is diagnosed with an infectious or viral disease, you should isolate him in a separate room.

To avoid pathological infections, it is better to have one (permanent) sexual partner and not to neglect barrier contraceptives.

FEVER OF UNKNOWN GENESIS honey.
Fever of unknown origin - an increase in body temperature above 38.3 ° C at least 4 times within 14 days due to an undiagnosed disease.
Possible reasons
Infectious and bacterial diseases
Abdominal abscesses
Mycobacterial infections
Cytomegalovirus
Sinusitis
HIV infection
Endo- and pericarditis
Kidney and urinary tract infections
Osteomyelitis
Infections caused by long-term functioning catheters
Amoebic hepatitis
Wound infections
Neoplasms
Lipoma
Leukemia
Solid tumors(hypernephroma)
Hepatoma
Atrial myxoma
Colon cancer
Collagen-vascular diseases
Giant cell arteritis
Periarteritis nodosa
Rheumatoid fever
SLE
Rheumatoid arthritis
Rheumatoid polymyalgia
Other reasons
Granulomatosis
Pulmonary embolism
Taking medications
Thermoregulation disorders
Endocrine diseases
Factors environment
Periodic fever
Cerebrovascular accident
Alcoholic hepatitis.

Clinical picture

An increase in body temperature is not the only manifestation of the disease
The type and nature of fever are usually uninformative
Symptoms accompanying an increase in body temperature are headaches, muscle pain, and general malaise.

Laboratory research

General and biochemical blood tests (possible leukopenia, anemia, thrombocytopenia or thrombocytosis; increased concentration of CRP; increased ESR)
Liver function tests (especially ALP) indicate inflammation, obstruction, or infiltrative lesions of the organ
Bacterial culture blood. Several venous blood cultures (no more than 6) are performed to check for possible bacteremia or septicemia
General analysis and bacterial culture of urine.

Special studies

Comprehensive examination of a patient for tuberculosis
For vigorous or acute infection, the tuberculin skin test is almost always negative (it should be repeated after 2 weeks)
Bacterial culture of urine, sputum and gastric lavage to identify the causative agent of tuberculosis
Serological studies are carried out for infections caused by Epsthna-Barr viruses, hepatitis, cytomegalovirus, pathogens of syphilis, Lyme borreliosis, Q-fever, amoebiasis and coccidioidomycosis. Testing for HIV infection is mandatory
Serum protein electrophoresis for suspected immune system pathology
Study of thyroid function in cases of suspected thyroiditis
Determination of RF and antinuclear AT in cases of suspected collagenosis and vascular pathology
X-ray of organs chest, abdominal cavity, paranasal sinuses (according to clinical indications)
CT/MRI of the abdomen and pelvis, radioisotope scanning(in combination with direct biopsy if indicated) if an infectious process is suspected and volumetric education
Ultrasound of the abdominal cavity and pelvic organs (in combination with a biopsy if indicated) if a mass formation, obstructive kidney disease or pathology of the gallbladder and biliary tract is suspected
Echocardiography for suspected valve damage, atrial myxoma, pericardial effusion.
Diagnostic procedures
Bone marrow puncture for suspected granulomatosis, malignant neoplasms
Liver biopsy for suspected granulomatosis
Temporal artery biopsy for suspected giant cell arteritis
Biopsy of lymph nodes, muscles and skin (if indicated)
If the diagnostic procedures performed turned out to be uninformative, a diagnostic laparotomy is performed.

Treatment:

Lead tactics

It is necessary to establish the cause of fever using all possible methods
If the etiology of fever remains unclear, repeat the history, physical examination, and screening tests. laboratory research. Particular attention should be paid to previous tourist trips, sexual contacts, endemic factors, and the effects of previously taken drugs
As body temperature rises, increase the amount of fluid consumed.
Drug therapy. The drugs of choice are prescribed depending on the underlying disease. If the cause of fever is not established (in 20%), the following drugs can be prescribed
Antipyretics (paracetamol or aspirin)
[acetylsalicylic acid]). Aspirin is not prescribed to children, because possible development of Reye's syndrome
Other prostaglandin synthetase inhibitors (indomethacin or naproxen)
Glucocorticoids (trial). After the use of glucocorticoids, relapse or activation of undiagnosed diseases (for example, tuberculosis) is possible.
Antibiotics (trial, based on medical history).

Course and prognosis

Depends on etiology and age
The one-year survival rate is: 91% for those under 35 years of age, 82% for those aged 35-64 years and 67% for those over 64 years of age.

Age characteristics

Children and teenagers. The most common possible causes are collagen-vascular diseases, infectious processes, inflammatory diseases intestines
Elderly
Possible reasons - acute leukemia, Hodgken's disease, intra-abdominal infections, tuberculosis and arteritis of the temporal artery
Signs and symptoms are less specific
Concomitant diseases and intake various drugs may mask fever
The mortality rate is higher than in other age groups.
Pregnancy. An increase in body temperature increases the risk of developing defects in the formation of the fetal neural tube and causes premature birth.
See also Giant cell arteritis. Chronic juvenile arthritis, HIV infection and AIDS, Systemic lupus erythematosus, Hepatoma, Wegener's granulomatosis, Cytomegalovirus infection, Infectious endocarditis

Causes of the disease

A febrile state that lasts no more than 1 week indicates an infection. It is assumed that prolonged fever is associated with the course of some serious pathology.

Fever of unknown origin in children or adults may be the result of an overdose of drugs:

antimicrobial agents;
antibiotics;
sulfonamides;
nitrofurans;
anti-inflammatory drugs;
medications prescribed for gastrointestinal diseases;
cardiovascular medications;
cytostatics;
antihistamines;
iodine preparations;
substances that affect the central nervous system.

The medicinal nature is not confirmed in cases where temperature values remain high within 1 week after discontinuation of the medication.

Causes of fever of unknown origin

Classification

Based on the nature of the course, fever of unknown origin occurs:

classical - against the background of pathologies known to science;
nosocomial - occurs in persons who are in the intensive care unit for more than 2 days;
neutropenic - there is a decrease in the number of neutrophils in the blood;
HIV-associated.

According to the level of temperature increase in LNG there are:

subfebrile - varies from 37.2 to 37.9 degrees;
febrile - 38–38.9 degrees;
pyretic - from 39 to 40.9;
hyperpyretic - above 41 degrees.

Based on the type of changes in values, the following types of hyperthermia are distinguished:

constant - daily fluctuations do not exceed 1 degree;
weakening - variability throughout the day is 1–2 degrees;
intermittent - there is an alternation of a normal state with a pathological state, the duration is 1–3 days;
hectic - there are sharp jumps in temperature indicators;
wavy - the thermometer readings gradually decrease, after which they increase again;
perverted - indicators are higher in the mornings than in the evenings;
incorrect - has no patterns.

Duration of fever of unknown origin can be:

acute - persists no longer than 15 days;
subacute - the interval is from 16 to 45 days;
chronic - more than 1.5 months.

Symptoms of the disease

The main, and in some cases the only, symptom of fever of unknown origin is an increase in body temperature.

The peculiarity of this condition is that the pathology over a fairly long period of time can be completely asymptomatic or with erased symptoms.

Main additional manifestations:

muscle and joint pain;
dizziness;
feeling of lack of air;
increased heart rate;
chills;
increased sweating;
pain in the heart, lower back or head;
lack of appetite;
stool disorder;
nausea and vomiting;
weakness and weakness;
frequent mood changes;
strong thirst;
drowsiness;
pale skin;
decreased performance.

External signs occur in both adults and children. However, in the second category of patients, the severity of associated symptoms may be much higher.

Diagnostics

Diagnosis of fever of unknown origin

The first step in establishing a correct diagnosis includes:

studying medical history - to look for chronic diseases;
collection and analysis of life history;
a thorough physical examination of the patient;
listening to a person using a phonendoscope;
measurement of temperature values;
a detailed survey of the patient regarding the first time of occurrence of the main symptom and the severity of concomitant external manifestations and hyperthermia.

Laboratory research:

general clinical and biochemical blood tests;
microscopic examination of feces;
general urine analysis;
bacterial seeding of all human biological fluids;
hormonal and immunological tests;
bacterioscopy;
serological reactions;
PCR tests;
Mantoux test;
tests for AIDS and HIV.

Instrumental diagnosis of fever of unknown origin involves the following procedures:

radiography;
CT and MRI;
skeletal system scan;
ultrasonography;
ECG and EchoCG;
colonoscopy;
puncture and biopsy;
scintigraphy;
densitometry;
EFGDS;
MSCT.

Densitometry

Consultations with specialists from various fields of medicine are necessary, for example, gastroenterology, neurology, gynecology, pediatrics, endocrinology, etc. Depending on which doctor the patient sees, additional diagnostic procedures may be prescribed.

Differential diagnosis is divided into the following main subgroups:

infectious and viral diseases;
oncology;
autoimmune diseases;
systemic disorders;
other pathologies.

Treatment of the disease

When a person’s condition is stable, experts recommend refraining from treating fever of unknown origin in children and adults.

In all other situations, trial therapy is performed, the essence of which will differ depending on the alleged provocateur:

for tuberculosis, anti-tuberculosis substances are prescribed;
infections are treated with antibiotics;
viral diseases are eliminated with the help of immunostimulants;
autoimmune processes are a direct indication for the use of glucocorticoids;
for gastrointestinal diseases, in addition to medications, diet therapy is prescribed;
if malignant tumors are detected, surgery, chemotherapy and radiotherapy are indicated.

If drug-induced LNG is suspected, it is necessary to discontinue the medications the patient is taking.

Prevention and prognosis

To reduce the likelihood of developing a pathological condition, it is necessary to adhere to preventive recommendations aimed at preventing the occurrence of a possible provoking disease.

Prevention:

maintaining a healthy lifestyle;
complete and balanced nutrition;
avoiding the influence of stressful situations;
preventing any injuries;
constant strengthening of the immune system;
taking medications in accordance with the recommendations of the clinician who prescribed them;
early diagnosis and comprehensive treatment of any pathologies;

Chronic pelvic pain syndrome (CPPS, formerly the term prostatodynia) in men is a chronic,

About,

FEVER OF UNCLEAR GENESIS: IS THE DECODING REAL?

Dvoretsky L.I.

The term “fever of unknown origin” (FOU) refers to situations that are often encountered in clinical practice, in which fever is the main or only sign of various diseases, the diagnosis of which remains unclear after a routine, and in some cases, additional examination. The spectrum of diseases underlying LNG is quite wide and includes various diseases infectious nature, malignant tumors, systemic vasculitis, as well as other diseases of various origins. In a small proportion of patients, the cause of fever remains undeciphered. LNG is based on common diseases with an unusual course. The diagnostic search for LNG includes the identification of additional clinical and laboratory signs that determine the nature of the targeted examination using the most informative for the given situation diagnostic methods. The question of the advisability of prescribing treatment, including a trial, before deciphering the LNG should be decided individually, depending on the specific clinical situation.

The term "fever of unknown genesis" (FUG) implies common clinical conditions wherein fever is a main or sole sign of different diseases whose diagnosis remains unclear after routine and, in some cases, additional studies. The range of diseases underlying FUG is rather wide and includes different diseases of infectious origin, malignant tumors, systemic vasculitis and other diseases of various genesis. FUG is caused by common diseases having an unusual course. In FUG, diagnostic search includes identification of additional clinical and laboratory signs that determine the nature of a goal-oriented examination by using the diagnostic methods which are informative for a specific condition. Whether it is advisable to prescribe treatment, including presumptive one, and to decipher FUG should be determined on an individual basis as a specific clinical situation requires.

L.I. Dvoretsky MMA named after. THEM. Sechenov

I.M.Sechenov Noscow Medical Academy

Even ancient doctors knew that an increase in body temperature was one of the signs of many diseases, which were often simply called “fever.” After the German clinician Wunderlich pointed out the importance of measuring body temperature in 1868, thermometry became one of the few simple methods objectification and quantitative assessment of the disease. After the introduction of thermometry, it was no longer customary to say

that the patient is suffering from a “fever.” The doctor's task was to determine the cause of the fever. However, the level medical technologies of the past did not always make it possible to reliably determine the cause of febrile conditions, especially long-term ones. Many clinicians of the past, who based their diagnosis only on personal experience and intuition, gained a high medical reputation precisely thanks to the successful diagnosis of febrile diseases. As old diagnostic methods improve and new ones emerge, progress has been made in deciphering the causes of many cases of fevers. However, to this day, prolonged fevers of unknown origin remain one of the diagnostic problems in clinical practice.

Probably, each clinician had to observe more than one patient with prolonged fever, which was the main or only sign of the disease, the diagnosis of which remained unclear after conducting the usual, and in some cases, additional examination. Such situations give rise to

a number of additional problems associated not only with the uncertainty of the diagnosis and delay of treatment for an indefinite period, but also with the patient’s long stay in the hospital, a large volume of examinations, often expensive, and loss of confidence of the patient in the doctor. In this regard, to designate such situations and allocate them to a special group requiring a specific approach, it was proposed

the term "fever of unknown origin" (FOU). This term has firmly entered the clinical lexicon and has become widespread in the medical literature, including number and in one of the most popular

reference and bibliographic publications "Index Medicus". Clinical practice and analysis of the literature indicate ambiguity in the interpretation and arbitrary use of the term LNG by some clinicians without taking into account the degree of temperature increase, its duration and other signs. This, in turn, makes it difficult to produce standard approach to a diagnostic search. Meanwhile, at one time, the criteria were precisely defined that made it possible to evaluate a clinical situation as LNG:

– the patient has a temperature of 38°C (101°F) or higher;

– duration of fever for 3 weeks or more or periodic rises in temperature during this period;

– uncertainty about the diagnosis after examination using generally accepted

(routine) methods.

Thus, a unique syndrome (LNG syndrome) was identified, which differs from other cases of increased body temperature. Based on these criteria, cases of so-called vague low-grade fevers, which are often incorrectly designated as LNG, should not be classified as LNG. Meanwhile, unclear low-grade fevers occupy a special place in clinical practice and require a different diagnostic approach. In most cases, vague low-grade fevers are one of the manifestations autonomic dysfunctions, although they may also be due to the presence of an infectious-inflammatory process (tuberculosis). An important criterion is the duration of fever for at least 3 weeks, and therefore short-term increases in temperature, even of unknown origin, do not meet the criteria for LNG. The last criterion (uncertainty of the diagnosis) is decisive and allows us to interpret the situation as LNG, since the information obtained during a standard (routine) examination of the patient does not allow us to decipher the cause of the fever.

The allocation of patients with LNG into a special group serves primarily practical purposes. It is necessary for doctors to develop the skills of a rational diagnostic search using adequate informative methods research based on knowledge of the characteristics of diseases manifested by LNG. The range of these diseases is quite extensive and includes diseases that fall within the competence of a therapist, surgeon, oncologist, infectious disease specialist and other specialists. However, until the true nature of LNG is deciphered, patients, as a rule, are in general therapeutic departments, less often in specialized departments, where they are admitted, depending on the nature of the existing symptoms, with suspected pneumonia, urinary tract infections, rheumatic and other diseases.

Nosological structure of the causes of LNG for Lately is undergoing changes. Thus, among the “febrile” diseases, some forms of infections in immunodeficiencies, various types of nosocomial infections, boreliosis, mononucleosis syndrome, etc. began to appear.

WITH Taking this into account, it was proposed to distinguish 4 groups of LNG:

1) “classical” version of LNG, which includes, along with previously known, some new diseases (Lyme disease, syndrome chronic fatigue); 2) LNG due to neutropenia;

3) nosocomial LNG; 4) LNG associated with HIV infection (microbacteriosis, cytomegalovirus infection, cryptococcosis, histoplasmosis).

This article will mainly discuss group 1 LNG. They are based not on rare or unusual pathological processes, but on good known to doctors diseases, features of the course

which is the predominance of febrile syndrome. These are, as a rule, “common diseases with an unusual course.”

Analysis of literature data and our own clinical experience indicate that most often LNG is based on diseases that can be conditionally divided into several groups. Specific gravity

each of these groups fluctuates, according to different authors, which can be determined by various

factors (specifics of hospitals, in which patients are examined, level of examination, etc.). So, the cause of LNG can be:

generalized or local infectious and inflammatory processes – 30–50% of all cases of LNG;

tumor diseases – 20–30%;

systemic connective tissue lesions (systemic vasculitis) – 10–20%;

other diseases, varied in etiology, pathogenesis, methods of diagnosis, treatment and prognosis - 10–20%;

in approximately 10% of patients the cause of fever cannot be deciphered

despite thorough examination using modern informative methods.

An increase in body temperature during these pathological processes is ultimately due to the effect of endogenous pyrogen on the thermoregulation center located in the anterior hypothalamus. Endogenous pyrogen, according to modern concepts, belongs to interleukins and is produced by macrophages, monocytes, neutrophils and, to a lesser extent, eosinophils as a result of the immune response to various microbial and non-microbial antigens, immune complexes, sensitized T-lymphocytes, endotoxins of various origins, products of cellular decay. Cells of various types also have the ability to produce endogenous pyrogen. malignant tumors(lymphoproliferative tumors, kidney tumors, liver tumors, etc.). Product fact tumor cells pyrogen has been proven experimentally and is confirmed in clinical settings disappearance of fever after surgical removal tumor or initiation of chemotherapy for a lymphoproliferative disease.

Infectious and inflammatory diseases

The presence of LNG is traditionally associated by most doctors primarily with an infectious process and prompts the prescription of antimicrobial drugs even before obtaining the examination results. Meanwhile, infectious and inflammatory processes underlie LNG in less than half of the patients in this group.

Tuberculosis

Various forms of tuberculosis (TB) continue to be one of the common reasons LNG, and among infectious and inflammatory processes, according to most publications, occupy a leading place. The latter is the cause of LNG in approximately half of patients after kidney transplantation. Infectious mononucleosis may proceed atypically and take a protracted course in the absence of altered lymphocytes and lymphadenopathy. A similar course gave rise to the so-called chronic mononucleosis syndrome. High sensitivity PCR has specificity for detecting the virus.

Special group infectious pathology in cases of LNG is HIV infection, the spread of which over the past decades in many countries has changed the structure of the causes of LNG. In this regard, a diagnostic search for LNG should, apparently, necessarily include examination for the presence of not only HIV infection, but also those infections that are often associated with AIDS (microbacteriosis, coccidioidomycosis, histoplasmosis, etc.).

Tumor diseases

The second place in the structure of causes of LNG is occupied by tumor processes of various localizations, including hemoblastosis. The most frequently diagnosed are lymphoproliferative tumors (lymphogranulomatosis, lymphosarcoma), kidney cancer, and liver tumors (primary and metastatic). Among other tumors, bronchogenic cancer, cancer of the colon, pancreas, stomach and some other localizations are detected.

According to the data available in the literature, there was practically no tumor localization that was not detected in cases of LNG of “tumor nature.” Taking into account the likelihood of the presence of a tumor of any localization in LNG, the oncological search in these patients should be aimed not only at the most vulnerable “tumor targets”, but also at other organs and tissues.

The main difficulties in timely recognition of the tumor process in patients with LNG are usually due to minimal local manifestations or their absence. In addition, the oncological search is often delayed due to the prevailing view of doctors on fever as a manifestation of a mainly infectious process, and therefore antibacterial drugs that do not affect the temperature are consistently prescribed.

In some cases, nonspecific syndromes such as erythema nodosum (especially recurrent), hypertrophic osteoarthropathy, migratory thrombophlebitis, and some others may suggest a tumor in LNG. Unfortunately, these signs are not always correctly assessed and are interpreted as paraneoplastic only in retrospect.

The mechanism of fever during tumor processes is probably associated with the products tumor tissue various pyrogenic substances (interleukin-1, etc.), and not with decay or perifocal inflammation.

One of the first signs of treatment effectiveness after starting therapy with cytostatic drugs for some hemoblastoses, such as lymphogranulomatosis, or surgical removal of the tumor, is the normalization of temperature. It is also possible that lymphokines with pyrogenic properties are produced by lymphocytes that are activated in response to the development of the tumor process. Fever does not depend on the size of the tumor and can be observed as with widespread tumor process, and in patients with the presence of one small tumor node. In this regard, it is appropriate to mention a case of LNG in a patient we observed with pheochromoblastoma, identified only at postmortem histological examination adrenal gland

Oncological search in patients with LNG should include non-invasive examination methods

(ultrasound, computed tomography, nuclear magnetic resonance), radioisotope scanning of lymph nodes, skeleton, organs abdominal cavity, puncture biopsies,

endoscopic methods, including laparoscopy, and, if necessary, diagnostic laparatomy. Immunological research methods should be used to identify some specific tumor markers, in particular, o-fetoprotein (primary liver cancer), CA 19-9 (pancreatic cancer), CEA (colon cancer), PSA (prostate cancer).

Identification of the above markers will allow for a more targeted diagnostic search to exclude tumor disease.

Systemic diseases

This group of diseases ranks third in frequency among the causes of LNG and is represented mainly by diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis, Still's disease in adults, various shapes systemic vasculitis (nodular arteritis, temporal arteritis, etc.), so-called cross syndromes (Overlaps).

Habitual diagnostic signs the above diseases are insufficiently expressed or absent during febrile debuts of SLE and other systemic vasculitis, when fever precedes the appearance of articular syndrome or other systemic disorders. In such situations, suspicion of systemic pathology, which determines the direction of the diagnostic search, may arise when dynamic observation for patients after identifying other clinical and laboratory signs. At the same time, it is important to correctly assess all symptoms that seem nonspecific or are usually associated

with the fever itself (myalgia, muscle weakness, headache and etc.). Thus, the combination of these symptoms with fever, especially with increase in ESR, gives reason to suspect diseases such as dermatomyositis (polymyositis), polymyalgia rheumatica, and temporal arteritis. Polymyalgia rheumatica maybe on initial stages manifest itself as fever in combination with pain in the proximal parts of the shoulder and pelvic girdle. You should pay attention to the elderly and senile age of patients, a sharp increase in ESR. Polymyalgia rheumatica is often combined with temporal arteritis, characterized by the appearance of localized headaches, thickening of the temporal

arteries with weakening or absence of their pulsation. Verification of the diagnosis is possible with the help of a biopsy of the so-called temporal complex, which can be obtained by examining the skin, muscle tissue, temporal artery. If there is a high probability of the disease, trial treatment with glucocorticoids in small doses (15–20 mg/day) is possible.

The effectiveness of the latter in this pathology is so specific that it may have

diagnostic value. However, the use of glucocorticoids as a trial of treatment should be avoided without a reasonable suspicion of systemic disease.

Still's disease in adults is more often diagnosed as a cause of prolonged fever - a disease with a less defined nosological framework and without specific laboratory signs.

Along with fever, the obligatory symptoms are arthritis (or arthralgia in the onset), maculopapular rash, and neutrophilic leukocytosis. Pharyngitis, lymphadenopathy, enlarged spleen, serositis, and myalgia are common. Rheumatoid and antinuclear factors are absent. This symptom complex makes one suspect various infections, sepsis and prescribe massive antimicrobial therapy, which turns out to be ineffective. The diagnosis is made rather by excluding infections and other systemic diseases.

Among the causes of LNG, rheumatic fever with the absence of microorganisms in the blood (abacterial endocarditis) and changing auscultatory symptoms remains relevant. The fever is resistant to antibiotics but can be treated with salicylates and glucocorticoids.

Other diseases

This heterogeneous group includes the most diverse diseases in etiology, diagnostic methods, treatment and prognosis. According to many authors, LNG in a number of patients may be based on diseases such as Crohn's disease, ulcerative colitis, diverticulitis, thyroiditis, granulomatous diseases (sarcoidosis, granulomatous hepatitis), thrombophlebitis of the veins of the leg and pelvis, pulmonary embolism, nonspecific pericarditis, benign peritonitis (periodic disease), chronic alcoholic hepatitis and a number of other diseases. The peculiarity of these diseases, diverse in their origin, is atypical course, manifested mainly by a febrile syndrome without clearly defined organ symptoms, which makes it difficult to decipher the nature of LNG.

Vascular thrombosis

In some patients, fever may be the only or one of the main manifestations of thrombophlebitis of the deep veins of the extremities, pelvis, or recurrent pulmonary embolism. Such situations occur more often after childbirth, bone fractures, surgical interventions, in the presence of intravenous catheters, in patients with atrial fibrillation, and heart failure. In case of deep vein thrombosis, qualified Doppler examination of the corresponding vessels may have some diagnostic value. Heparin can completely stop or reduce fever within 48–72 hours, while antibiotics are not effective. Taking into account

Therefore, if this pathology is suspected, it is possible to prescribe a trial treatment with heparin, the effect of which may have diagnostic value and determine the further management of patients.

Thyroiditis

In almost all publications, among the diseases detected in LNG, there are isolated cases thyroiditis, in particular its subacute forms. Local symptoms and signs of dysfunction of the thyroid gland that are usual for subacute thyroiditis are not leading in these situations. Absent or weak expression pain syndrome at first does not allow the doctor to include this disease in the diagnostic search. In this regard, sufficient attention is not always paid to the examination of the thyroid gland (examination, palpation), which could determine the direction of the diagnostic search. Sometimes it is possible to obtain information (usually retrospectively) about short-term pain or discomfort in the neck. To exclude thyroiditis in cases of LNG may be useful ultrasonography thyroid gland scan.

Drug fevers

Fever accounts for 3–5% of adverse drug reactions, and is often the only or main complication.

Drug fevers can occur at various intervals (days, weeks) after the prescription of the drug and do not have any specific signs to distinguish them from fevers of other origins. The only sign of the medicinal nature of fever should be considered its disappearance after discontinuation of the suspected drug.

Normalization of temperature does not always occur in the first days, but often several days after discontinuation, especially in case of violations drug metabolism, slow excretion of the drug, as well as damage to the kidneys and liver. However, in most cases, with persistent high temperature within a week after discontinuation of the drug, the medicinal nature of the fever becomes unlikely

Fever most often occurs when using the following groups of medications:

– antimicrobial drugs (penicillins, cephalosporins, tetracyclines, isoniazid, nitrofurans, sulfonamides, amphotericin B);

– cytostatic drugs (bleomycin, asparaginase, procarbazine);

– cardiovascular drugs (alphamethyldopa, quinidine, procainamide, hydralazine);

– drugs acting on the central nervous system (diphenylhydantoin, carbamazepine, chlorpromazine, haloperidol, thioridazine);

– anti-inflammatory drugs (aspirin, ibuprofen, tolmetin);

– various groups of drugs, including iodide, antihistamines, clofibrate, allopurinol, levamisole, metoclopramide, cimetidine, etc.

Artificial fevers

Artificial fevers are caused by manipulation with a thermometer, as well as by ingestion or injection under the skin or into the urinary tract of various substances with pyrogenic properties. In such situations, most often we're talking about about a special type mental disorders with hypochondriacal manifestations, characterized by a painful concentration on the state of one’s own health, careful scrupulous observation of the slightest changes in well-being and condition (body temperature, blood pressure, bowel function, etc.). Such patients are characterized by a certain type of behavior that is difficult to explain from a generally accepted point of view, for example, the desire for multiple examinations, often invasive (some patients insist on surgical interventions). Patients believe that they are suspected of malingering and underestimate the severity of their condition, the seriousness and danger of the disease. Perhaps in this regard, they strive to demonstrate more obvious and objective signs of the disease, such as fever, bleeding, thereby trying to attract the attention of doctors. The behavior described should not be considered

In clinical practice, situations often arise when, against the background of good health, the patient’s natural body temperature suddenly increases (the indicator often exceeds 38°C). Moreover, such prolonged hyperthermia may be the only symptom that indicates some disturbance in the body. But numerous diagnostic studies do not allow us to determine a specific pathological process. In this case, the attending physician diagnoses the patient with “fever of unknown etiology” and gives a referral for a more detailed health examination.

A fever lasting more than 1 week is most likely caused by a serious illness. As practice shows, hyperthermia in approximately 90% of cases is an indicator of the occurrence of an infectious process in the body, the presence of a malignant neoplasm, or damage to connective tissues of a systemic nature. In rare cases, prolonged fever indicates an atypical form of the course of common diseases that the patient has encountered more than once in his life.

There are the following causes of fever of unknown origin:

In medicine, several types of fever have been studied and identified depending on the nature of changes in body temperature over time:

Permanent (stable type). The temperature is high (about 39°C) and remains stable for several days. Fluctuations during the day do not exceed 1°C (pneumonia).
Relaxing fever. Daily fluctuations are 1-2°C. The temperature does not drop to the usual level (diseases with purulent tissue damage).
Intermittent fever. Hyperthermia alternates with the patient's natural, healthy state (malaria).
Wavy. The increase in temperature occurs gradually, followed by the same systematic decrease to a low-grade level (brucellosis, lymphogranulomatosis).
Wrong fever. During the course of hyperthermia, there is no pattern in the daily change in the indicator (flu, cancer, rheumatism).
Return type. Elevated temperature (up to 40°C) alternates with low-grade fever (typhoid).
Perverted fever. The morning temperature is higher than in the afternoon (diseases of viral etiology, sepsis).

Based on the duration of the disease, acute (less than 15 days), subacute (15-45 days) or chronic fever (over 45 days) are distinguished.

Symptoms of the disease

Usually the only and pronounced symptom of prolonged fever is increased body temperature. But against the background of hyperthermia, other signs of an unknown disease may develop:

increased work of sweat glands;
suffocation;
chills;
pain in the heart area;
dyspnea.

Diagnosis of fever of unknown origin

Standard diagnostic procedures for prolonged fever syndrome:

Blood and urine tests (general), detailed coagulogram.
Biochemical study of blood from the ulnar vein. Clinical data will be obtained on the amount of sugar, sialic acids, total protein, AST, CRP in the biomaterial.
The simplest diagnostic method is the aspirin test. The patient is asked to take an antipyretic tablet (paracetamol, aspirin). After 40 minutes, observe whether the temperature has decreased. If there is a change of even one degree, it means that an inflammatory process is occurring in the body.
Mantoux test.
Three-hour thermometry (measurement of temperature indicators).
X-ray of the lungs. Used to determine such complex diseases as sarcoidosis, tuberculosis, lymphoma.
Ultrasound of organs located in the abdominal cavity and pelvic area. Used in cases of suspected obstructive kidney disease, neoplasms in organs, or pathologies of the biliary system.
ECG and EchoCG (it is advisable to perform if there is a possibility of atrial myxoma, fibrosis of the heart valves, etc.).
CT or MRI of the brain.

If the above tests do not reveal a specific disease or their results are controversial, then a series of additional studies are prescribed:

Studying information about possible hereditary diseases.
Obtaining information about the patient's allergic reactions. Especially those that arise from the use of medications.
Study of tissues and mucous membranes of the gastrointestinal tract for tumors and inflammatory processes. For this, endoscopy, radiation diagnostics or biopsy are used.
Serological blood tests, which are prescribed for suspected hepatitis, HIV infection, cytomegalovirus, amoebiasis, syphilis, brucellosis, infections caused by the Epstein-Barr virus.
Microbiological analyzes of various types of patient biomaterial - urine, blood, nasopharyngeal secretions. In some cases, a blood test for intrauterine infections is necessary.
Microscopic analysis of a thick drop of blood (to exclude the malaria virus).
Collection and analysis of bone marrow puncture.
Study of blood mass for the so-called antinuclear factor (exclusion of lupus).

Differential diagnosis of fevers is divided into 4 main subgroups:

association of common infectious diseases.
oncological subgroup.
autoimmune pathologies.
other diseases.

During the differentiation procedure, a specialist must pay attention not only to those symptoms that bother a person at a given time, but also to those that he has encountered previously.

It is necessary to take into account the surgical operations performed, chronic diseases and psycho-emotional characteristics of each individual patient. If a person takes any medications for a long time, he must inform the diagnostician about this.

Treatment of the disease
Drug therapy will be prescribed based on the characteristics of the underlying disease. If it has not yet been detected, but there is suspicion of an infectious process, the patient must be hospitalized.

At home, you can carry out a course of antibiotic therapy (using penicillin rad medications). The use of non-steroidal antipyretics is permitted.

Prevention of fever of unknown origin

Prevention, first of all, consists of quick and correct diagnosis of diseases that cause a persistent increase in temperature over a long period of time. At the same time, you cannot self-medicate, choose even the simplest medications yourself.

A mandatory preventive measure is the constant maintenance of a high level of immune protection. If one of the family members is diagnosed with an infectious or viral disease, they should be isolated in a separate room.

To avoid pathological infections, it is better to have one (permanent) sexual partner and not to neglect barrier contraceptives.