Photosensitizers and sunburn. Photosensitivity or solar dermatosis

Antibiotics or antimicrobials are drugs derived from bacteria and fungi, as well as through chemical synthesis. They are used in the treatment of infectious diseases. Antibiotics either kill microorganisms or prevent them from multiplying.

The choice of the necessary antibiotic depends on the sensitivity of microorganisms, the severity of the disease, the toxicity and allergy of the patient. In some cases, a combination of several antibiotics is required.

What antibiotics can provoke an allergy

There are several groups of antibiotics, among which are aminoglycosides, macrolides, sulfonamides and quinolones. Penicillin is the best known and oldest antibiotic used to treat numerous infectious diseases. In principle, antibiotics are harmless to subjects who take them, although they can sometimes cause wide range side reactions.

Antibiotics can be a strong allergen

Some people are predisposed to developing allergies to antibiotics. They get skin rashes, swelling, fever, arthritis, or other symptoms when treated with these drugs. Most often, such a reaction of the body occurs after treatment with drugs of the penicillin group or sulfonamides.

Preparations from other groups of antibiotics can also cause an allergic reaction in the body, but the manifestations will not be so severe. It has also been established that the reaction of the anaphylactic type of organism is often provoked by antibiotics from the penicillin group.

The main causes of allergy to antibiotics

So far unknown exact reason, due to which allergic reactions occur in some patients treated with antibiotics.

The rash may be an allergy to antibiotics.

A number of factors have been identified that affect the likelihood of its occurrence:

the patient has allergic manifestations on other drugs and food;
chronic diseases;
frequent repeated courses treatment with the same antibiotic;
unreasonably large doses taking the drug;
genetic predisposition.

If a person has had allergic reactions to penicillin, then the likelihood of such a reaction to another antibiotic increases by about 3 times. Depending on the method of administration of the drug and the characteristics of the organism, the rate of occurrence of the reaction can vary from 1 hour to 3 or more days.

Symptoms of urticaria, its manifestation on the skin

Urticaria is an allergy to antibiotics (skin rash). Treatment with such drugs causes the formation of small red seals and blisters, similar to nettle burns. Sometimes blisters reach up to 10 cm in diameter. The rash spreads almost all over the body, but often on the extremities.

Itching that accompanies hives is worse in the evening and at night

At the same time, the whole body can itch, and not just the areas on which the rash appeared. From the start of treatment to the onset of signs of urticaria, it can take up to 2 weeks.

Itching is a phenomenon that accompanies the rash in most cases.

As a rule, after stopping treatment, a skin rash can persist for two days. Scar marks or age spots on the body, after getting rid of urticaria, does not remain.

Quincke's edema as a reaction to antibiotics

Quincke's edema occurs for several reasons, but more often it appears as an allergy to food or drugs, mainly in people who are allergic to other irritants. Children and young women are most susceptible to Quincke's edema.

If you suspect Quincke's edema, you should immediately call an ambulance or doctor

Swelling of the deep layers of the skin and mucous epithelium may be a reaction to the treatment of infectious diseases and indicate that an allergy to antibiotics has arisen. For most, this may present with a rash on the skin. With angioedema, fluid accumulates in the deep layers, and the surface of the skin does not change its color. It can appear on the hands, genitals, eyes and legs. Itching is absent.

Symptoms may worsen over 1-2 days

If the swelling affects the upper Airways, life-threatening suffocation may occur. After discontinuation medicines edema is eliminated. But in severe cases, they are prescribed antihistamines and steroids.

Note! Quincke's edema in severe cases may affect internal organs, including the meninges and joints. In this case, the manifestations of the disease can develop rapidly and require urgent medical intervention.

Skin rash after taking antibiotics

According to statistics, more than 20% of the population had a problem with the appearance of rashes on the body. Approximately 1-2% of patients develop such an allergy to antibiotics (skin rash). The treatment of this disease is aggravated in people suffering from such serious diseases as leukemia, HIV, monoculosis and cytomegalovirus infection.

A rash is just one symptom of an allergy.

Rash - an allergic reaction with a change in the affected area skin. Not only the color changes, but also the texture of the affected skin. Rashes are localized in a certain area, but can spread throughout the body.

Except external signs, such a manifestation of an allergy may be accompanied by other symptoms: itching, swelling, soreness or peeling of the skin. This causes not only aesthetic problem but also general malaise.

Signs of ALLERGY to antibiotics may appear only after 3 weeks from the day you start taking

The longer the course of antibiotic use, the Great chance occurrence allergic reaction organism, in particular, such as a rash on the skin.

Photosensitization: symptoms and manifestations

A small part of the population develops such a disorder as photosensitivity, characterized by an allergy to ultraviolet light, even with short contact with sunbeams. Such an effect can appear after a few seconds, and sometimes this period is delayed up to 2-3 days.

Photosensitivity - Allergy to sunlight

The disease is characterized by reddening of the skin in the form of a sunburn.. This state is accompanied painful sensations and itching. With more strong reaction body, pigmentation is disturbed in the affected areas, the skin thickens, swelling and blisters appear. In some people, this process can affect not only areas that have been in direct contact with the sun's rays, but also those places that have not been exposed to ultraviolet radiation.

Photosensitivity is often observed in infants, in persons with chronic diseases or those who have recently suffered serious illness. This can be provoked by chemicals used in everyday life, cosmetics or be a reaction such as an allergy to antibiotics (skin rash).

An allergic reaction to household chemicals may occur

Treatment of such a reaction can only consist in protecting from contact with the rays of the sun. If antibiotics cannot be canceled, then cotton clothing should be used for this period, covering the body as much as possible, an umbrella or a wide-brimmed hat.

The manifestation of allergy to antibiotics in childhood

The number of children who are allergic to antibiotic treatment is increasing every year. Such a negative reaction to antibiotics in a child, the so-called hypersensitivity of the immune system, occurs during treatment. Mostly this reaction of the body manifests itself after taking drugs from the penicillin group.

The most common signs of such a pathology in a child are headache, diarrhea, stomach pain, rhinitis, conjunctivitis, itching of the skin. An allergic reaction can manifest itself in the form of hives, swelling of the eyelids and lips (angioedema), itching, rashes similar to those that appear with measles or chicken pox.

Children are prone to allergies sometimes more than adults.

In a small number of patients childhood other symptoms may also occur. The danger of an allergy to antibiotics lies in the fact that in addition to the external forms of manifestation of a reaction to treatment, in the form of a rash on the skin, the internal organs of the child may suffer.

It can manifest itself in the form of such reactions as anaphylactic shock, feeling of suffocation, vomiting, diarrhea, dizziness and even loss of consciousness. Symptoms can develop quite quickly. In these cases, it is necessary urgent appeal to the hospital for emergency action.

Antibiotic Allergy Treatment

If after the start of taking the drug there is an allergy to antibiotics (skin rash), the treatment of the disease must be adjusted and measures taken to get rid of negative symptoms. Knowing how to deal with a rash and recognizing a more severe reaction can help you feel better, and maybe save a life.

Knowing how to behave, you can take the necessary measures in time

If you suspect an allergic reaction, you should immediately contact your doctor and ask for help.. The antibiotic to which the reaction occurred should be discontinued, and before starting the next treatment, it is necessary to warn the medical staff about the adverse reaction.

Allergen replacement

If during antibiotic treatment redness of the skin, itching or other manifestations occur, the drug should be discontinued, because the patient's condition worsens with each dose of the allergen. After the antibiotic has been discontinued, the condition gradually improves.

Before prescribing new antibiotic, the doctor will refer the patient for a reaction test

But to continue treatment, another antibiotic should be selected. It is selected from the following group of drugs, having previously made a reaction test.

Important to remember! If an allergy to some group of antibiotics has already occurred, then there is a high probability of such a reaction occurring again. In this case, as a rule, a drug from the following group of antibiotics is prescribed, taking into account the age of the patient and the course of the underlying disease.

Antihistamines

Signs of an allergy to antibiotic treatment in the form of a rash on the skin, swelling of the mucous membranes, impaired performance gastrointestinal tract, arrhythmias, occur when released into blood vessels free histamine.

Antihistamine drugs increase the number of white blood cells in the blood and reduce the production of histamine, which forms the immune system in response to the allergen. Depending on the patient's condition, the doctor may prescribe the following antihistamines: Loratadine, Cetirizine, Diphenhydramine.

Antihistamine

Their doses will depend on a number of factors, including the age of the patient and the characteristics of the body. You should carefully study the instructions for using the medication.

Such drugs are not recommended for children under 4 years of age and elderly patients., as dizziness, irritability, drowsiness may occur. antihistamines, causing drowsiness should not be taken with antidepressants sleeping pills and powerful painkillers.

Attention! Pregnant women and women who are breastfeeding should not use antihistamines. These drugs may cause side effects in children or cause birth defects in the fetus.

This method of getting rid of allergies is used for long-term treatments and if other methods failed to get rid of a negative reaction.

The essence of this method is the introduction of a small amount of the allergen subcutaneously for long period. The dose of the injected allergen is constantly increasing, for the body to gradually get used to it.

Desensitization - the introduction of an allergen under the skin

But the disadvantage of desensitization is that it is not possible to completely get rid of the manifestation of an allergy, it can only decrease the level of sensitivity to the allergen. The duration of treatment in this way can reach up to 5-6 years. But if the result from this method is not noticed during the first 2 years, then the treatment is stopped.

Folk recipes for eliminating skin rashes

An alternative to the treatment of allergies to antibiotics with medicines is traditional medicine. There are several ways to get rid of a skin rash. The most simple and affordable way- treatment medicinal herbs: nettle, celery, yarrow, hawthorn, valerian or lemon balm.

Decoction of medicinal plants

The affected areas are moistened with a prepared decoction from a medicinal plant 2-3 times a day. The decoction is prepared by 10-minute infusion in a water bath 1 tbsp. l. herbs in 200 ml of boiling water.

Celery

Celery juice is consumed before meals for half an hour, 1 tsp. Juice is prepared from fresh plant on a juicer, or by pressing, grated on a fine grater, plants.

Plant to get rid of skin rashes

Hawthorn

You can make tea from hawthorn, letting it brew for 30 minutes. Take 50 ml 20 minutes before meals for 2 weeks.

To minimize the possibility of allergies during antibiotic treatment, it is worth strengthening the immune system. This requires a dietary adjustment vitamin complexes, as well as using folk remedies to block the painful reaction of the body.

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8 981 0 Hello dear readers of our site. What do you know about allergies to the sun and ultraviolet radiation? Today we will talk about such a phenomenon as photosensitivity or photodermatitis.

What is photosensitivity?

photosensitization (from the Greek foto - light and lat. sensibilisatio - irritation) — hypersensitivity skin and mucous membranes to light radiation (ultraviolet, sunlight or other visible radiation). Photosensitization manifests itself in the form of allergic reactions (photodermatitis, burns, etc.) and phototoxic effects.

Any person is subject to phototoxic manifestations, regardless of age, gender and skin color. Photoallergic reactions are associated with immune processes and are inherent in people called photosensitized.

Symptoms of photodermatitis occur immediately or after a while. It can be:

sunburn in the form of red spots;
swelling;
burning and itching;
soreness of the affected areas of the skin;
dermatitis;
weeping lesions;
blisters or blisters;
ulcers;
exacerbation of chronic skin diseases - eczema, psoriasis.

Phototoxic manifestations may persist for a long time. The mechanism of the appearance of phototoxic reactions is that under the influence of ultraviolet radiation substances on the skin and in the skin are broken down, toxic formations are formed that affect the skin. Photoallergies occur due to the combination of such toxins with body proteins.

Substances that cause photoallergic and phototoxic reactions are called photosensitizers, i.e. substances-irritants or provocateurs. It is they who, under the influence of visible light (sun, UV lamp in the solarium) provoke manifestations of photosensitivity.

Endogenous and exogenous photosensitizers

Exogenous sensitizers

Phototoxic substances that act and enter the body from the outside are called exogenous photosensitizers. They can enter through food, respiratory tract, through direct contact with the skin - drugs, creams, ointments, household chemicals, plants, perfumes.

Most often, body reactions are caused by exogenous photosensitizers. These include:

chromium salts used in metals, alloys, in the technology of leather tanning and dyeing;
eosin, a chemical dye found in cosmetics such as lipstick;
cosmetic components - musk, amber;
sulfanilamide, antihistamine and corticosteroid ointments, topical creams;
tar;
plants - sorrel, quinoa, angelica, hogweed;
components of ethyl alcohol;
nutritional supplements;
arsenic;
essential oils - bergamot, lemon, etc.
procedures associated with exfoliation, peeling;
medicines for internal use;

drug sensitization

When taking many drugs and exposure to ultraviolet radiation on the skin, many people experience photosensitivity. This form of its manifestation is called drug photosensitivity. It manifests itself against the background of admission:

some types of tetracyclines - terramycin, biometsin;
sulfa drugs;
barbiturates;
phenothiazines;
hormonal drugs (including contraceptives);
neuroleptics;
cardiovascular funds;

Drug photosensitivity can also be immediate and delayed. Severe sunburns, redness, itching, tingling, a rash like dermatitis, up to the formation of edema and ulcers, occur on the skin.

Endogenous photosensitizers

Endogenous sensitizers are substances involved in the production of important enzymes in the body, which are in excess or deficiency - porphyrins, bilirubin, cholesterol, bile acids. Under the influence of ultraviolet radiation, they are able to cause photoallergic and phototoxic reactions.

Listed below are some of the diseases sunlight in combination with these endogens:

Porphyrins are natural or synthetic chemicals involved in the production of heme, which subsequently forms hemoglobin. Increased amount porphyrins in the body is called porphyria - genetic disease. In porphyria, it affects nervous system, liver and skin. Exposure to light radiation provokes the appearance of blisters, ulcers, and erosions on the skin with porphyria. The most common form of this disease is called tardive cutaneous porphyria. It manifests itself against the background of taking medications and during insolation. Therefore, it often manifests itself in spring and summer, when the sun is most active. Symptoms include brown pigmentation of the skin and teeth, slight skin vulnerability, blisters and ulcers form at the site of skin lesions, leaving scars. From the side internal systems there is a violation of the function of the liver, the cardiovascular system.

Another disease provoked by endogenous photosensitizers is polymorphic dermatosis. Its course proceeds like eczema in acute form. The causes of this disease are not fully understood. Medical scientists believe that polymorphic dermatosis occurs against the background of disorders of the gastrointestinal tract and hormonal imbalance.
Light pox - under the influence of sunlight, a rash occurs in the form of small bubbles, accompanied by itching, nausea, loss of strength. Flows by type chicken pox. The mechanisms of occurrence have not been fully elucidated. It can be accompanied by a rash not only on the skin, but also on the mucous membranes. Boys and men are mostly affected.
Pigmentary xeroderma is a hereditary disease manifested by solar radiation in the form of changing and progressive pigmentation, atrophy of the affected areas, conjunctivitis or other eye lesions. Inflamed areas of the skin form malignant changes in its cells. It is considered a precancerous condition of the skin. It appears in early childhood.
Chronic actinic dermatitis is inflammation of the skin from exposure to radiation (sun, UV radiation from lamps, radiation). Manifested in redness, swelling with itching, burning. After it goes into peeling. In severe form, there is pinpoint bleeding, necrosis, thickening, scarring.

Photosensitivity Correction

If phototoxic and photoallergic reactions are detected under the influence of the sun or artificial UV radiation, first of all, you should contact medical specialists. Only a doctor can determine the sources and methods for correcting photosensitivity.

As a diagnostic, a photoprobe is used to determine the biodose of radiation with and without sensitizers. After that, a course of correction is prescribed, including the elimination of the source of photosensitization, the exclusion of contact with provoked exogenes. It is important to find out the nature of photosensitivity in the victim - phototoxic reaction or photoallergic.

Here is a table for comparison:

signs	Phototoxicity	Photoallergy
Beginning of manifestation	instant	delayed
Number of factors	some	one two
area affected	directly on the exposed areas	not only in the affected areas
Types of manifestation	sunburn	eczema, dermatitis
The nature of the mechanism	not immune	immune

If present endogenous mechanisms sensitization, then the correction comes down to treating the underlying disease or reducing photosensitivity, limiting exposure to the sun, and using protective equipment from UV radiation.

With drug photosensitivity, if it is impossible to stop taking medications, you should protect your skin from the sun as much as possible, and be less exposed to insolation. This is especially true for the peak of solar activity in spring and summer.

It is possible to prescribe drugs to reduce the photosensitivity of the skin after a thorough examination.

For skin lesions, creams, ointments, and lotions prescribed by a doctor are used.

The use of photosensitivity in physiotherapy

Photosensitization methods have been successfully used in physiotherapy. Thanks to many sensitizers, photosensitizer drugs have been developed that, under the influence of radiation, activate chemical processes on cellular and molecular levels. In addition, photosensitizers are able to accumulate in cells and under the emission of light waves and oxygen oxidation can modify these cells.

These properties have proven to be useful for the use of physiotherapeutic methods - photochemotherapy and photodynamic therapy in the treatment of such diseases:

psoriasis;
leukoderma;
neurodermatitis;
vitiligo;
alopecia;
skin mycoses;
tumor foci.

Prevention of photosensitivity

If you have photosensitive skin or are at risk for photosensitivity, then prevention of phototoxic and photoallergic manifestations is important.

In order to avoid sunburn, allergic effects and more severe manifestations of photosensitivity, it is recommended to adhere to the following measures:

Protect skin from excessive exposure to the sun - light clothing that covers arms, shoulders, the presence of a hat and sunglasses. It is better to prefer clothes made from natural and breathable fabrics.
Use of UV cosmetics with a suitable SPF factor.
Take vitamins regularly.
Do not go out in the sun with applied cream containing a fatty composition.
Avoid direct sunlight when tanning.
Limit sun exposure during peak hours (from 11 a.m. to 3 p.m.).
Carefully study the composition of food products, cosmetics in order to identify photosensitizing components.
Protect skin from sun exposure after peeling and tattooing.
Use nourishing masks for the skin.
The sea with photosensitivity can provoke its manifestations, but is not contraindicated if precautions are observed. It is not recommended to visit places near the sea with a very hot climate, where solar activity is intense.

The opinion of doctors about the problem of photodermatitis. What to do? How to protect yourself?

08.07.2015

An analysis of the data collected by the European pharmacovigilance authorities has shown that sensitization reactions to sunlight are quite common (about 10% of cases), especially in the spring and summer. In more detail about this problem, we talked with Dr. medical sciences, Professor of the Department of Phthisiology and Pulmonology of the National Medical Academy postgraduate education them. P.L. Shupik Sergey Viktorovich Zaikov.

What is photosensitivity and what causes it?
– The phenomenon of photosensitivity is an increased sensitivity of the body (usually skin and mucous membranes) to the action of ultraviolet (range 320-400 nm) or visible (range 400-800 nm) radiation. Photosensitivity reactions can occur at any age in representatives of all races and proceed both in an immediate and in a delayed manner. Famous whole line chemical substances, which, accumulating in the skin, cause photoallergic, phototoxic reactions, as well as other photodermatosis in areas of the skin exposed to light irradiation.
In a photoallergic reaction, a chemical substance (drug) contained in the skin absorbs photons and forms a new compound, a kind of "photoproduct". This modified compound binds to cytoplasmic or membrane proteins to form an antigen. Photoallergic reactions occur only in some people who are exposed to ultraviolet (UV) rays while taking medications, which is associated with the characteristics of their immune system. These reactions may be limited to the site of application of the drug, or they may appear on other areas of the body exposed to sunlight and adjacent areas. The first use of the drug leads to sensitization, and skin rashes appear only when it is used again (delayed-type allergic reaction). The most common cause of photoallergic reactions are halogenated salicylanilides for external use, benzocaine (included in soap and other detergents), amber musk (found in aftershave lotions).
Drugs that can cause photosensitivity, photoallergic and phototoxic reactions with a frequency of 1 episode per 1-10 thousand cases of their use include:
- non-steroidal anti-inflammatory drugs, analgesics-antipyretics - ibuprofen, piroxicam, ketoprofen, diclofenac, indomethacin, fenbufen, phenylbutazone;
- antibiotics and antimicrobials- trimethoprim, sulfonamides, doxycycline, tetracycline, minocycline, oxytetracycline, fluoroquinolones (lomefloxacin, ciprofloxacin, ofloxacin, sparfloxacin), pipemidic acid, nalidixic acid, ceftazidime, amoxicillin, griseofulvin;
- H 1 - and H 2 blockers - promethazine, diphenhydramine, ranitidine, cimetidine;
- drugs used in cardiology - digitoxin, amiodarone, fibrates, statins, furosemide, methyldopa, minoxidil, nifedipine;
- neuroleptics, sedatives and antidepressants - doxepin, preparations based on St. John's wort, amitriptyline, fluoxetine;
- antidiabetic drugs - chlorpropamide, glibenclamide;
- essential oils - lime, orange oil, bergamot oil, as well as the juice of parsley, lupine, angelica officinalis, angelica forest and some types of hogweed.
Photoallergic contact dermatitis (FACD) can be classified under several rubrics. international classification ICD-10 diseases: L23.2 - allergic contact dermatitis caused by cosmetics; L23.3 - allergic contact dermatitis caused by drugs in contact with the skin; L23.8 - allergic contact dermatitis caused by other substances; L56.2 - Photocontact dermatitis. FACD, which is one of the types of photoallergic reactions (Fig. 1, 2), was considered a rarity several decades ago, but now its prevalence has increased significantly.

Rice. 1. Photoallergic dermatitis

Rice. 2. FAQD

So, in Spain since 1996 it has been going detailed information regarding cases of FACD. It was noted that most of the reactions occurred after local application ketoprofen (Fig. 3), less often they developed after the use of piroxicam and etofenamate.

Rice. 3. FACD while taking ketoprofen

Under the influence of sunlight, in particular UV, ketoprofen is transformed into a substance that causes the development of hypersensitivity. In 2004, scientists from Belgium assessed the risk of developing FACD with topical use of ketoprofen. It was found that FACD manifested itself predominantly acute inflammation skin covers. Observations were made on patients with rashes after the use of ketoprofen, previously exposed to insolation. FACD was accompanied by the appearance of a papulovesicular rash with itching, bullous elements, and erysipelas-like lesions. In one of the 20 examined patients, photosensitivity persisted for about 4 months.

IN last years It has been established that the development of FACD is based on hypersensitivity of the skin, mediated by T-lymphocytes in response to the action of a photoallergen in a patient who has previously been sensitized by a causally significant chemical or antigen that can provoke cross-allergic reactions. The mechanism of formation of photoallergens under the influence of UV irradiation or light in the visible part of the spectrum is not completely known. There are currently two possible mechanisms for their formation:
a) a specific molecule that is capable of absorbing light - the chromophore - can go from a stable state to an activated one; as a result, a certain amount of energy is released, which is able to return the molecule to its normal state;
b) a stable photocompound is formed, in some cases, through interaction with the carrier, forming a full-fledged antigen; in the future, FACD develops according to the mechanism of ordinary contact dermatitis:
Langerhans cells process this antigen and present it (together with class II MHC antigens) in the lymph nodes to T cells;
circulating activated T-lymphocytes are delivered to sensitized skin areas and recognize the photoallergen;
skin changes occur (mainly allergic contact dermatitis).
The clinical manifestations of FACD are the same as those of an eczematous reaction, and the histopathological presentation is identical to other forms of allergic contact dermatitis. FACD is usually characterized by well-defined changes corresponding to surfaces exposed to light: face, neck, top part V-shaped chest backside hands and forearms and sometimes lower legs. A one-sided reaction may occur if a photoallergen is applied to any part of the body and subsequent exposure to the sun or due to greater exposure to one side of the body. However, the photoallergen can be transferred from one part of the body to another, for example to the contralateral areas, by crossing the legs or by using the hands (ectopic dermatitis). A special distribution of changes can sometimes be a consequence of the "marital" FACD. In addition, there may be no change at the site of initial application, and subsequent exposure to the sun results in reactions in both exposed and unexposed areas, as has been found for ketoprofen. The duration of the reaction to the action of light after the termination of the application of the photoallergen is different and depends on the type of photocombination. Yes, for sunscreens the duration of this reaction is less than 4 days, and for ketoprofen - up to several weeks after the termination of its topical application. Skin changes usually disappear after contact with the photoallergen is stopped, but sometimes they can recur even after its elimination.
Phototoxic reactions are not caused by immune mechanisms. The reason for their development is the accumulation medicinal substance solar energy and its subsequent transfer to the skin, which can cause damage or cell death. In this case, skin lesions appear only on those parts of it that are exposed to sunlight, and resemble a severe sunburn. The lesion does not go beyond the irradiated areas. Phototoxic reactions are realized in the form of erythema, edema, the appearance of vesicles and blisters (pseudoporphyria). Hyperpigmentation often occurs. If melanin accumulates in the epidermis, the skin becomes brown shade if in the dermis it is gray (this often happens while taking chlorpromazine and amiodarone). Unlike a normal sunburn, a phototoxic reaction can persist for a long time. Photoreactive substances can exacerbate chronic skin diseases(eczema, herpetic infection, psoriasis, acne), accelerate skin aging, cause the development of skin cancer.
Thus, drug photosensitivity is a distorted skin reaction to UV radiation or visible light against the background of the action of drugs (for local and general use) or chemicals (cosmetics, pesticides, herbicides, etc.). Phototoxic reactions can occur in any person and proceed as a sunburn (erythema, edema, blisters). Photoallergic reactions occur only in sensitized individuals and are mediated by immune mechanisms (rashes are represented by papules, vesicles, weeping, lichenification). The severity of skin reactions depends on chemical nature irritant, concentration, duration of exposure, intensity and length of light waves, duration of exposure, skin's ability to absorb light (determined by the thickness of the stratum corneum, the amount of melanin, secretion of the skin glands).

– Can photoallergic reactions be caused by the use of cosmetics?
– The cause of sensitization is often cosmetic and perfumery products containing musk, amber, bergamot oil, sandalwood oil, certain antibacterial agents, components of food additives (certain sweeteners), aids(cadmium sulfate), used, for example, when applying tattoos. Photoallergic reactions often occur after applying funds to the skin, but their development is also possible with the systemic use of drugs. UV rays can cause structural changes cosmetic product, which is associated with the appearance of hypersensitivity, and also has a local irritating or damaging effect on the skin.

- If a particular substance has photosensitizing properties, is the development of phototoxic or photoallergic reactions inevitable?
– No, but the likelihood of this increases significantly if the following conditions are present:
if the skin is under the influence of retinoids, since the latter enhance the exfoliation of the stratum corneum, accelerate skin renewal, and also increase skin sensitivity to UV radiation;
after any procedures aimed at exfoliating the stratum corneum (peels), since all types of them (chemical peels, laser resurfacing and even home peels) reduce the skin's resistance to UV radiation;
when used in daytime cosmetics, vegetable oils containing polyunsaturated fatty acid, because they quickly oxidize in the sun, resulting in the release of reactive oxygen species and other oxidation products that are toxic to the skin. In turn, UV radiation also leads to the formation active forms oxygen in the skin;
after tattoo (for permanent makeup sometimes pigments containing cadmium salts are used, which have photosensitizing properties);
after procedures with essential oils;
when using sunscreens containing para-aminobenzoic acid.
As mentioned above, skin photosensitivity can also increase with the use of a number of foods, which include:
food products containing furanocoumarins and related substances (for example, figs, grapefruit and some other citrus fruits, parsley root, dill);
vegetables and fruits rich in carotenoids (carrots, parsnips);
some medicinal official and unofficial plants, especially from the rue and umbrella family (angelica officinalis, wild carrot, St. green wheat, barley, mustard, green onion, garlic, agave);
chicken eggs.

– What diagnostic methods are optimal in this case? clinical situation?
– If phototoxic or photoallergic reactions are suspected, phototesting is carried out, the biodose of UV radiation is determined (without / with withdrawal of the test substance). In favor of a phototoxic reaction is evidenced by an increase in biodose after the withdrawal of the photosensitizing substance, the dose-dependent nature of the reactions, their rapid occurrence (within a few hours after application). In the diagnosis of photoallergic reactions, application phototests are also used. They are carried out in the same way as conventional application tests, only photoallergens are applied in two rows and one of the rows is exposed to UV radiation (the dose should be less than the biodose). Inflammatory reaction develops only in the area with the applied photoallergen subjected to irradiation. Persistent solar erythema is characterized by a low biodose of UVR and a wide damaging range of radiation.
In addition, it is very important to differential diagnosis between phototoxic and photoallergic reactions (table).

– What is the treatment algorithm for patients with photoallergic and phototoxic reactions?
– The treatment of patients with photosensitivity in the first place is to eliminate the substance that caused it and limit exposure to the sun. In the acute course of a phototoxic reaction, topical glucocorticoids and non-steroidal anti-inflammatory drugs for oral administration are used. In more severe cases, analgesics and a short course of systemic glucocorticoids and cytostatics (eg, azathioprine, cyclosporine, or cyclophosphamide) may be required. In the treatment of photosensitivity, it must be taken into account that some H 1 blockers sometimes cause such a reaction by themselves. Phototoxic reactions resolved after discontinuation of the drug or with the use of UV protection. Photoallergic reactions may persist after discontinuation of the drug. Since some drugs are present in the skin long time, insolation can provoke the development of a relapse even a few weeks after its cancellation.

– How to avoid the development of photosensitivity?
– Prevention of the development of phototoxic and photoallergic reactions is based on the knowledge of the above causes and mechanisms of their development. So, the warnings of doctors about the dangers of UV radiation must be taken seriously. Going out in the spring and summer, you need to use sunscreen or give preference to day cream and decorative cosmetics with UV filters. Should not be applied to the skin before going out nutritious cream, since it may contain polyunsaturated fatty acids and other photosensitizers. On a sunny day, it is best to wear a wide-brimmed hat and try not to spend a lot of time in the sun. Cosmetic procedures, accompanied by skin exfoliation, it is more rational to carry out in the fall or winter, and not in the spring and summer months. After the peeling procedure, the skin should be protected with a sunscreen with maximum protection (SPF>50). More care should be taken to protect the skin from sun exposure when taking medicines and food supplements with potential photosensitizing properties. In the spring-summer period, you should use cosmetics containing antioxidants - vitamins E, C, plant polyphenols, which reduce the effects of UV radiation on the skin. In addition, persons with high risk the development of photosensitivity, it is necessary to avoid the use of perfumery products containing furanocoumarins from natural sources(bergamot, lavender, lemon, rosemary, sandalwood oils), which can also sensitize the skin to sunshine. Ambergris, used in aftershaves and colognes, can also cause skin to react to UV rays. Some products contain dyes that can cause reactions when exposed to UV radiation, such as eosin (lipsticks, lip gloss), erythrosin, fluorescein, methylene blue, violet, neutral red, rose bengal, toluidine blue, tripaflavin, trypan blue. When choosing a product applied to the skin during active sun exposure, it is necessary to carefully study its composition. It is desirable that the skin is clean before tanning, and in case of prolonged exposure to the sun, it is necessary to use protective equipment, avoid exposure to direct sunlight. It is not recommended to sunbathe during hours of high solar activity!

Prepared Elena Molchanova

STATS BY THE TOPIC Allergy and Immunology

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With drug photosensitivity, the rash is localized mainly on open areas of the body, but can also spread to closed areas.

Drugs that cause phototoxic and photoallergic reactions when ingested include chlorpromazine, tetracyclines, thiazide diuretics, two NSAIDs (benoxaprofen and piroxicam), and fluoroquinolones. The pathogenic range of radiation corresponds to the absorption spectrum of the photosensitizing substance. For drugs that cause phototoxic reactions, this is almost always UV-A. Phototoxic reactions resolved after discontinuation of the drug or with the use of UV protection. On the contrary, some photoallergic reactions persist after discontinuation of the drug. Since they can be triggered not only by UV-A, but also by visible radiation, which all transparent sunscreens pass through, it is very difficult to treat photoallergic reactions.

Phototoxic and photoallergic reactions are treated in the same way as sunburn. The main principles are drug withdrawal and protection from sunlight (mainly ultraviolet radiation). Since the drug can remain in the skin for a long time, insolation can provoke a relapse even several weeks after its withdrawal. Sometimes the increased sensitivity to sunlight persists for several months or years. This state is known as

Photodermatosis - inflammatory process on the skin as a result of increased sensitivity to both direct and reflected sunlight. Lack of therapy can lead to serious damage to the epidermis.

A variety of predisposing factors can provoke the development of a dermatological anomaly, ranging from the occurrence of autoimmune processes to the use of low-quality cosmetics.

Photodermatoses have nonspecific features that are characteristic of other skin diseases. The main symptoms are considered to be redness, itching of the skin, swelling, peeling, the appearance of multiple rashes by type.

To confirm the diagnosis, you should seek help from a dermatologist or allergist. The diagnostic process is A complex approach and includes a thorough physical examination, a number of laboratory and instrumental procedures.

Treatment of photodermatosis is carried out only conservative ways. The therapy is oral intake And local use medicines. The use of non-traditional methods is not excluded.

Etiology

Photodermatosis - allergic to sun and ultra-violet rays, but the sunlight itself does not contain allergens. The increased sensitivity of the skin is stimulated by substances located on the skin - photosensitizers.

The pathogenesis lies in the fact that under the influence of sunlight are released and activated free radicals- unstable particles in the body that react with proteins. Against this background, new combinations are formed - antigens that can act as a trigger for the allergic process.

The reaction of the human body may be as follows:

phototraumatic effect. It develops due to prolonged exposure to direct sunlight, especially from 10 am to 4 pm. Burns occur on the skin.
Phototoxic. It is caused by the uncontrolled use of drugs both orally and in the form of injections. Blisters, swelling and redness are noted.
Photoallergic. Occurs when the human immune system perceives ultraviolet light as foreign and dangerous influence. The skin becomes rough, covered with small rashes.

There are many photosensitizers adverse factors, which are usually divided into external and internal.

The first group combines substances that fall directly on the surface of the skin:

powders, detergents and other means household chemicals;
medicines;
cosmetical tools, especially those containing sandalwood oil, benzocaine, bergamot oil, amber, musk, benzophenone;
sap that is released on contact with certain plants.

Internal sources:

burdened heredity;
the presence in the history of any allergic reaction;
increased rates body mass index;
irrational use of drugs - in case of non-compliance daily allowance and duration of administration prescribed by the doctor;
course of organ pathologies digestive system, since the process of neutralization and removal of toxins is disrupted -, and;
dysfunction of the endocrine system;
inadequate intake of human body vitamins and nutrients;
any diseases that lead to a decrease in immune resistance;
psychosomatic influence.

It should be noted that the development of the disease is influenced by a completely harmless factor - the consumption of certain food products:

carrot;
parsley;
bell pepper;
figs;
celery;
citrus;
alcohol;
natural coffe;
seafood;
dried fruits;
nuts.

Quite rarely, certain plants act as photosensitizers, after accidental or deliberate contact with which an increased susceptibility to sunlight is formed. This category of provocateurs includes the following herbs:

nettle;
orchid;
hawthorn;
fraxinella;
quinoa;
sedge;
sagebrush;
hogweed;
St. John's wort;
immortelle;
clover;
buttercups.

One of the predisposing factors may be an overdose of drugs:

antibacterial substances;
antifungal agents;
hormones;
antidepressants and tranquilizers;
corticosteroids;
drugs to normalize the functioning of the heart.

Not only the indiscriminate use of medications can cause inflammatory lesion skin, but also their one-time use, subject to further prolonged exposure to sunlight or UV rays. If a person knows that he will spend a lot of time in the sun, it is better to stop using drugs.

All sources of pathology lead to skin lesions in both adults and children.

Classification

Photodermatoses are not one disease, but a whole group, the diseases of which have the same causes of occurrence and an almost identical symptomatic picture.

The disease has the following forms of course:

. The skin of the upper limbs and face is affected. The epidermis acquires a bright red hue, covered with small bubbles, cracks and erosions.
Polymorphic photodermatosis(sun pruritus). The open areas of the body are involved in the pathology - the neck, head, hands and shoulders. The main difference from the previous version is the tendency of bubbles and nodules to merge into big spots or plaques.
Pigmentary xeroderma is a fairly rare hereditary disease. The foci of peeling and hyperpigmentation of the skin are characteristic, after which their atrophy occurs.
. Spots and nodules, blisters of various sizes form on open areas of the skin. Such neoplasms can merge with each other and form plaques or weeping erosions.

Symptoms

The manifestation of the first clinical signs is observed even after a short stay of a person under direct sunlight or other sources of UV radiation. In some cases, no more than 20 seconds is enough, in others, the symptoms develop 1–2 hours after the influence of the provoking factor.

In children, photodermatosis is represented by such external manifestations:

increased tearing;
nasal congestion;
rashes on the skin that cause severe itching;
swelling of the lips;
redness of the face.

These symptoms are very similar to common allergies.

In an adult, the symptoms of photodermatosis will be more extensive and pronounced:

thickening and peeling of the stratum corneum of the skin;
severe itching and burning;
general malaise;
increase in temperature indicators;
the formation of nodes, blisters, vesicles, cracks and erosions on the surface of the skin;
excessive hairiness of the skin area involved in the pathology;
increased sensitivity of the skin to mechanical irritation;
or, conversely, depigmentation;
light intolerance;
expansion of capillaries and the appearance of vascular "asterisks";
bouts of dizziness and headache;
the formation of scars and ulcers at the site of burst blisters;
persistent nausea;
decrease in work capacity.

The intensity of the manifestation of clinical signs is determined by several factors - the provocateur and the time spent under the sun's rays or ultraviolet radiation.

Diagnostics

To confirm the diagnosis of photodermatosis, an allergist or dermatologist does not need only information about the symptoms. The process of diagnosing without fail should take an integrated approach.

Diagnostics includes the following activities:

familiarization with the history of the disease - to identify the internal causes of the development of malaise;
collection and analysis of life history - to ascertain the external provoking factor;
careful study of the condition of the skin;
palpation of the affected area of the skin;
detailed survey;
general clinical and biochemical blood tests;
general analysis urine, Zimnitsky test;
hormone tests;
skin biopsy;
specific photo tests;
radiography;
ultrasonography;

Polymorphic photodermatosis, like other types of pathology, should be differentiated with the following diseases:

solar
"Soderm";
"Bepanthen".

The use of non-traditional methods is not prohibited. The use of folk remedies is allowed. This treatment aims to healing decoctions and infusions for oral administration, use as lotions or as bath additives.

The most effective components:

marjoram;
fir;
aloe juice;
liquorice root;
passionflower;
geranium;
celandine;
marigold;
burdock root;
pine branches;
cereals;
fir cones.

In extremely severe cases, they turn to minimally invasive procedures - cryodestruction, laser vaporization and dosed UV radiation.

Prevention and prognosis

To prevent the occurrence of a problem, you should only follow a few simple preventive rules:

completely eliminate the influence of provoking photosensitizers;
refuse to stay in direct sunlight without first applying protective agents to the skin;
wear protective clothing;
eat right and balanced;
use enough liquids per day - at least 2 liters;
take medications according to the recommendations of the attending physician;
timely treat pathologies that can cause inflammatory skin lesions;
regularly complete preventive examination in a medical facility.

The prognosis of photodermatosis in most cases is favorable. With complex treatment and conscientious observance of the rules of prevention, it is possible to achieve full recovery. It is worth noting that the most common consequence of the disease is relapse.