Urticaria as a manifestation of drug allergy

Allergy to drugs in the form of urticaria (urticaria) is the most common pathological reaction of the immune system to medications and herbs. Its symptoms are often confused with symptoms of a food allergy or a nervous rash. Drug-induced urticaria is considered a harmless allergic manifestation, but it should be taken into account so as not to provoke more serious complications.

Reasons for appearance

An allergic reaction after taking medications or herbs can be caused not only by the patient’s immediate high sensitivity to the components of the drug. In addition to individual intolerance to the components of the drug, urticaria occurs in the following conditions:

• Genetically determined slow metabolism of medications. The concentration of the active substance in the blood may remain high, provoking an allergic reaction .
• One-time intravenous administration of large doses of drugs.
• Overdose of medications.
• The use of several medications that are prohibited to be combined due to their chemical composition.
• Concomitant use of certain medications and alcohol.
• Excess dosage or unreasonable intake of multivitamins (mainly A and C).
• Disorders of the kidneys and liver that slow down the removal of drugs from the body.

The presence of other allergies and viral infections are risk factors for drug-induced urticaria. However, even with this prerequisite, it is impossible to accurately predict the appearance of characteristic blisters after administration. In many ways, the likelihood of an allergic reaction is determined by the group of drugs taken.

What drugs often cause an allergic reaction?

Drug-induced hives can be caused by any chemical with varying degrees of likelihood.

The highest risk of an immune response is observed when taking the following groups of antibiotics:

• penicillin (Amoxiclav);
• cephalosporin (Ceftriaxone, Cephalexin);
• tetracycline (Doxycycline, Vibramycin);
• sulfonamide (Albucid, Ftalazol);
• aminoglycosides (Gentamicin, Neomycin);
• fluoroquinolones (Levofloxacin, Norfloxacin);
• Levomycetin.

In addition to antibacterial drugs, the following types of drugs can also cause drug-induced urticaria:

• opiates (codeine, morphine);
• NSAIDs (Indomethacin, Aspirin);
• analgesics (Tempalgin);
• barbiturates (Phenobarbital);
• antidepressants (Cipralex);
• statins (Lipitor);
• alkaloids (papaverine, atropine), herbal medicines;
• blood substitutes (dextran);
• a preparation for binding iron (desferam);
• protamine sulfate (a medicine that neutralizes the effect of heparin);
• anesthetics (lidocaine, novocaine);
• iodine-containing preparations (Lugol's solution);
• vitamins A, C, group B.

Symptoms of urticaria may appear after the administration of certain vaccines (Pentaxim, DTP, Priorix, BCG, etc.).

As a rule, a once-induced reaction persists in the future. This is due to the mechanism of interaction of the allergen with specific proteins (immunoglobulins E).

Even medications that have been used previously successfully without side effects can cause an allergic reaction in the form of hives. Not only patients are at risk, but also healthcare workers who often come into contact with various drugs.

Features of the course of medicinal urticaria

Drug-induced urticaria can develop not only by an immunological mechanism. If you are sensitive to the components of the drug, the first entry of an allergen into the body is accompanied by the production of antibodies, which accumulate and attach to special mast cells and basophils. They store active substances - in particular, histamine and heparin, which are released into the blood upon contact with the medication. This causes the blood vessels to dilate and increase their permeability to blood components, which leads to swelling and blistering.

There is also a non-immune mechanism for the release of histamine. It is realized due to the ability of some drugs (for example, Indomethacin, Aspirin, etc.) to act on mast cells directly, without the participation of immunoglobulins. The symptoms of non-allergic drug-induced urticaria do not differ from the manifestations of allergies externally, but have a number of diagnostic signs and relatively simple ways to solve the problem. One of them is to administer medications slowly.

Development speed

According to the speed of manifestation, drug-induced urticaria can be:

• instantaneous (the allergy appears after a few minutes);
• fast (1-2 hours pass from taking the medicine to the first symptoms);
• prolonged (may appear 1-2 weeks after the drug enters the body).

Cure time

As a rule, manifestations of drug-induced urticaria disappear several hours (up to 1-2 days) after the start of antihistamine therapy and the end of taking the drug to which the patient is allergic.

Treatment of allergies in children

Treatment of allergies in children has a number of common features. The fact is that the drugs used to treat allergies in children belong to the same groups. Parents often ask the question: “How to treat allergies in a child?” Next, we will consider the treatment of allergies in a newborn child, an infant and older children. The most common groups for allergy treatment are:

1. Hormones . This refers to the use of glucocorticosteroids, which have the most pronounced antiallergic effect. They are available in the form of ointments, sprays, inhalers, solutions for inhalation, tablets, ampoules for intramuscular and intravenous administration. For atopic dermatitis, local glucocorticosteroids are used in the form of ointments and creams. These include: elocom, celestoderm, lokoid, cutivate, dermovate. For allergic rhinitis, preference is given to local inhaled glucocorticosteroids: Nasonex, Avamis. They have a good effect in the treatment of seasonal allergies in children to flowering plants. With the development of bronchial asthma, inhaled glucocorticosteroids (ICS) are used for constant basic treatment: fluticasone, pulmicort. Systemic hormones – prednisolone – can be used. It is worth noting that in addition to treatment with hormones, for bronchial asthma in some cases it is possible to use cromones (Tyled, Intal) and leukotriene modifiers (akalate, montelukast). They also have an antiallergic effect and help prevent the development of attacks in children with asthma. For urticaria and Quincke's edema, hormones are administered immediately by intramuscular and intravenous injections. Preference is given to a 3% prednisolone solution; dexamethasone can also be used.
2. Antihistamines. They have a less pronounced effect, but have fewer side effects and contraindications. The essence of the action of these drugs is to block histamine receptors. This eliminates the effect of histamine. Histamine is a mediator of inflammation, that is, a substance that triggers allergies. They exist of different generations. First generation drugs include: diphenhydramine, tavegil, diazolin, suprastin, etc. They have side effects - sedative (hypnotic, sedative). It is worth highlighting suprastin. One of the most common drugs in this group. Has a pronounced antihistamine effect. It is available both in tablet form and as an injection solution, which allows it to be used to relieve acute allergic reactions. Second-generation drugs include: fenistil, allergodil, loratadine, etc. Among third-generation drugs, it is worth highlighting: Zyrtec, Telfast. Antihistamines are available in various forms: tablets, syrups, injection solutions. For atopic dermatitis and allergic rhinitis, tablets are often used. In young children it can be used in the form of syrup. For acute allergic reactions (urticaria, Quincke's edema), injection solutions are used. It is worth noting that this group of drugs is used to treat allergies even in a month-old baby.
3. Sorbents . They do not have a direct antiallergic effect, but indirectly have this effect. Allows you to remove allergens that cause allergies from the intestines. It is very important to use these drugs at certain times in relation to other drugs, as they can interfere with their absorption and, therefore, reduce the concentration of these drugs in the blood. Among the drugs in this group it is worth noting: enterosgel, atoxil, polysorb, sorbex, lactofiltrum.

To choose the right treatment tactics, consult a doctor.

Symptoms of the disease

Drug-induced urticaria in most cases occurs in an acute form and its duration does not exceed 6 weeks. The main signs of the disease include:

• sudden severe itching;
• hyperemia (redness) of the skin;
• rash in the form of characteristic blisters.

Redness, swelling and rash associated with drug-induced urticaria can be seen in the photo below: these symptoms can appear in specific areas of the body or throughout the entire skin.

The skin most susceptible to rashes is on the bends of the limbs, face, neck, and abdomen. In rare cases, the rash covers the mucous membranes of the nose and mouth, eyelids and genitals. If there are blisters in the mouth, swelling of the larynx occurs, making swallowing and breathing difficult.

A rash that covers the entire skin, as in the photo below, is more common in children. Otherwise, in young patients, urticaria is more severe than in adults: the rash is accompanied by weakness and fever.

In addition to rashes and itching, the disease can manifest itself:

• headaches;
• increased temperature;
• bronchospasm;
• difficulty breathing;
• itching on mucous membranes;
• runny nose;
• secretion of tears;
• impaired functioning of the kidneys and cardiovascular system.

Drug-induced urticaria, unlike other subtypes of the disease, is often accompanied by atypical symptoms: aching joints, the appearance of blood in the stool and cutting pain in the abdomen.

How long does the allergy last?

Allergies in a person can last a long time, for some - for a lifetime. In some cases, it is short-term, for example, when the immune system malfunctions.

It is almost impossible to predict the exact time and find out when the allergy will end. This is influenced by many factors.

Depending on the type of allergic reaction, the duration varies:

1. The hives do not go away for about a week.
2. If a skin rash appears, it disappears after three days, but leaves behind traces in the form of peeling on the body.
3. If there is itching on the affected area of ​​the skin, then after taking the medicine it disappears within a day. If a person scratches the skin and it becomes inflamed, the treatment will take longer.
4. In the case of allergic rhinitis, the disease resolves immediately after the isolation of the allergen, which contributed to the inflammation of the mucous membrane in the nose.

Diagnostics

An important diagnostic measure is taking an anamnesis. The allergist is obliged to find out a detailed treatment regimen and clarify the presence of a hereditary tendency to allergic reactions. In addition, the following are carried out:

• General urine and blood tests.
• Immunological tests (immunoglobulin E level, enzyme immunoassay, Shelley test, sublingual test, etc.).

General blood and urine tests help confirm the absence of infections that could cause hives. An increase in eosinophils in the blood indicates an allergic reaction .

In some cases, the level of immunoglobulins, as well as eosinophils, may be within normal limits. Then specific tests are used to determine pseudo-allergy. As a rule, it is distinguished by the dependence of the reaction on the amount of the provoking substance and the absence of constant exacerbations with repeated contacts.

How to diagnose allergies?

The first manifestations of an allergic reaction can be diagnosed in children under 1 year of age. At this time, their digestive organs are formed. For the first time, children experience characteristic allergy symptoms: rash and redness on the cheeks.

They are associated with a violation of the intestinal biocenosis or with disfermentation, when the child’s digestive tract does not produce enzymes to break down many products (these are functional characteristics of the body of an allergic child). By 2-3 years, these signs may disappear.

To prevent other skin manifestations from joining in the future, you need to detect and accurately diagnose the problem in time.

It is necessary to act in stages:

1. Understand whether it is an allergy or not.
2. If there is an allergy, determine how high the allergic background is and how much the process will worsen.
3. Determine what exactly the reaction is to.

To find out the allergen:

• carry out skin tests; the scarification method causes severe redness of the skin of infants, so the test is usually carried out from 5 years of age; prick tests, or prick tests, are also recommended for babies older than six months;

• donate blood to determine specific immunoglobulins and specific allergens in the blood serum;
• carry out a thorough history taking to clarify all the nuances.

Treatment of urticaria

Treatment of urticaria caused by medications begins with identifying and stopping the allergen. You can speed up the healing process with the help of enemas and enterosorbents (activated carbon, Polysorb). A diet that excludes alcohol, fatty foods and common food allergens (chocolate, nuts, eggs, red vegetables and fruits) is recommended.

Medications

Patients are prescribed the following drugs:

• Antihistamines (Suprastin, Cetirizine, Loratadine). They block histamine receptors and gradually stop the symptoms of urticaria.
• Antipruritic ointments (Akriderm, Fenistil). These drugs alleviate the patient's condition and reduce the chance of infection of damaged skin.
• Glucocorticosteroids (Dexamethasone, Prednisolone). Prescribed for complications and generalized urticaria.
• Miramistin solution for washing rashes on the mucous membrane.

Folk recipes

Traditional medicine is unable to help with the main cause of drug-induced urticaria, but can relieve symptoms and have an antiseptic effect on the skin. Baths with the following herbs have a calming effect:

• Chamomile. Pour 1-4 tablespoons of dried flowers into 0.5 liters of boiling water, leave in a water bath for 15 minutes and leave for another half hour.
• In succession. Pour 50 g of dry herb into 0.5 liters of hot water, cover with a lid and heat in a water bath for 20-25 minutes. Let it brew for an hour. Infusion and heating can be replaced by cooking for a quarter of an hour over low heat.
• Oak bark. Pour 80-100 g of raw material into 0.5 liters of boiling water and boil for 10 minutes.

Strained infusions can be added to a bath of warm water.

The intake of herbal decoctions internally is agreed with the attending physician . It is possible to use tinctures of valerian and hawthorn (dissolve 15 drops in a glass of water, drink before bedtime), calamus powder (0.5 teaspoon at night, washed down with water), yarrow decoction (1 tablespoon per 200 ml of boiling water, leave for 30 minutes, drink 3 times a day) and other remedies.

Prevention of urticaria

To prevent drug allergies in the form of urticaria, you must:

• Promptly inform your doctor about medications to which an immune reaction has occurred in the past.
• Avoid self-medication, especially with antibiotics.
• Do not prescribe additional vitamin complexes without consulting your doctor.

It is not recommended to introduce new foods (especially potential allergens) into the children's diet for 1-2 days before and after vaccinations. Before vaccination, patients of any age should be carefully examined for hereditary predisposition to allergies, infections and helminthic infestations .

What does a rash on the stomach look like?

The appearance of the rash depends on the specific cause of its appearance. The rash spots can be large or small, merge with each other or be scattered. Elements of the rash differ in color and structure from the surrounding healthy tissue. The rash can be either deep red or barely noticeable pale pink.

A rash on the abdomen may appear as:

• transparent bubbles;
• swelling blisters with fluid;
• crusts;
• keratinized scales;
• spots with a raised rim;
• spots that rise above the surface of healthy skin;
• flat spots.

The intensity of itching, which is a constant companion to the rash, varies from almost complete absence to unbearable, and depends on the underlying disease. Moreover, areas of rashes tend to have a higher temperature than intact skin.