Allergy is a pathological immune response to repeated contact with an allergen. It is manifested by a pronounced sensitivity to the irritant in the form of skin, eye, respiratory and intestinal reactions. Allergy treatment combines a complex of measures to eliminate the symptoms and causes of abnormal immune system reaction with prevention of recurrent disease recurrence.
According to statistics, 40% of the world’s population has allergies. Possible manifestations: runny nose, lacrimation, skin rashes, swollen mucous membranes, hyperemia, nausea, etc. People’s reactions to the same irritant may vary: for example, in one person shrimp cause nausea, in another – mucous membrane swelling and choking, in a third – skin rashes. Modern medicine uses a complex and comprehensive approach, which allows not only to accurately identify the allergen, but also to choose an effective course of treatment.
Allergy diagnosis methods
The tests are performed with the so-called “allergy panels”. There are many allergen panels for skin and immunological tests (food, pediatric, household, etc.), so the doctor first prescribes tests from that group to which a reaction is most likely to occur.
Skin test method
This is the easiest and fastest way to detect an allergen. It allows to obtain qualitative and quantitative information about a possible irritant: qualitative data are necessary to identify the fact of sensitization, quantitative – to determine the threshold of patient’s skin sensitivity. It is realized by introducing tenfold dilutions of allergens in order to calculate the starting dose of hypersensitization manifestation. These data are subsequently used for treatment.
There are several types of skin tests:
Scarifying is the primary method. Allergen solutions are applied drop by drop to the inner surface of the forearms, and then the skin is scratched with a scarifier. The reaction to the penetration of the allergen into the skin layers may occur within the first 15-20 minutes (immediate type allergic reaction). A papule with redness and swelling forms around the wounds from the scarifier. If it is larger than 2 mm, the reaction is considered positive. Final conclusions can only be drawn after 48 hours (delayed-type allergic reaction). A variation of the scarification test is the prick test. The main difference is that they use a thin insulin needle together with a scarifier.
Applicative tests are performed without violating the integrity of the skin, mainly in the diagnosis of contact dermatitis. Allergen solutions are applied to the interscapular area of the back in the form of a strip with swabs soaked in various allergens. Results appear as a rash or redness at a rate of half an hour to 48 hours – depending on the type of allergic reaction (immediate or delayed type).
Subcutaneous tests – an allergen solution is injected directly under the skin with a syringe, similar to the Mantoux test.
No more than 15-20 allergens are tested at a time, so in some cases the examination may be delayed. Depending on the severity of the symptoms, the diagnosis with skin allergy tests is made using the direct or indirect method. The direct method is exactly as described above. With the indirect method, an injection of serum with antibodies to the allergen in question is made beforehand in the area where the allergen is injected. This allows you to avoid anaphylactic shock if you have severe hypersensitivity to the irritant.
The result of a skin allergy test may appear as positive, weakly positive, questionable, negative Depending on this, the doctor makes a final diagnosis or prescribes additional examinations.
Synopsis! It is worth remembering that a single-component allergy with a reaction to only 1 allergen is extremely rare. Cross-action of several irritants in a polyvalent allergy is more likely to occur.
There are 3 groups of blood tests in the diagnosis of allergies:
general clinical analysis;
Test for specific immunoglobulins.
The first two tests are used for rapid diagnosis. They give general indirect information about the presence of a pathological immune reaction and are the reason for an in-depth examination.
General blood count (GBC)
The CBC is done in expanded form with determination of the leukocyte formula. Suspicion of allergy is caused by:
increased leukocyte count – in comparison with an infectious process, the excess of the norm is insignificant; mainly the number of eosinophils is increased;
A high level of eosinophils indicates not only the presence of allergies, but also inflammation, bacterial infection, the presence of worm infestation.
The analysis determines the content in the blood of special proteins produced by lymphocytes – immunoglobulins. When the body comes into contact with an irritant, the protective function is activated, and lymphocytes release nonspecific immunoglobulins of class E into the blood. They are responsible for the manifestation of immediate (fast) reactions and can remain in the bloodstream for up to 5-10 days. With delayed-type reactions, the titer of IgG will increase.
Blood test for allergen-specific immunoglobulins
Specific diagnosis is performed to identify a specific allergen or group of allergens, while determining the nature of the reaction: IgE – immediate type reaction, IgG – delayed type reaction. This is important not only to eliminate contact with the irritant, but also to choose an appropriate treatment tactic. Methods:
Admission involves complete exclusion of contact with a possible irritant. It is convenient in cases where visiting an allergist and conducting a full examination is not possible. The method is as follows: the “suspected” substances are completely removed from the patient’s environment for 2 weeks, and the patient’s condition is observed. If it has improved, the allergen is found. In this way the method simultaneously acts as a simple therapeutic technique.
Types of allergic rash
In adults, skin rashes appear in 20% of allergic reactions. It is an inflammation of the skin in the form of spots, nodules, papules, peeling, accompanied by itching and burning. A distinction is made between:
Represents a chronic genetically determined sensitivity to allergenic irritants. It accounts for 40% of all skin reactions. It manifests itself mainly in the face, neck, arms, and joint folds (elbows, knees, ankles) as swollen spots of different colors and pronounced itching.
Treatment: pharmacotherapy with antihistamines and anti-inflammatory drugs, in severe cases – corticosteroids. Parallel elimination therapy with elimination of the main allergen, immunotherapy, as well as symptomatic treatment with sanation of lesions and moistening of the skin.
Refers to immediate reactions with an increase in IgE levels only. It occurs quickly, within 1-2 days (sometimes within a few minutes), which makes it difficult to diagnose the allergen. Externally, it appears as large raised blisters of varying color, similar to burns on nettles.
Treatment: 2nd generation antihistamines, mainly in the form of external application – ointments, creams, gels. Additionally conduct treatment with sedatives to stabilize the psycho-emotional background.
Acute inflammation of the skin and mucous tissues as a result of the body’s allergic response to the toxic effects of medications, household chemicals, industrial substances, food products. It manifests as a variety of rashes in the form of spots, blisters, papules with intense itching and burning.
The reaction develops mostly of the delayed type – 1-21 days after contact with an irritant. It is accompanied by symptoms of severe intoxication with fever, palpitations, nausea, vomiting, impaired consciousness. In the bullous form, large (up to 5 cm in diameter) blisters with serous content appear in the inguinal and axillary folds. The most severe form of toxicoderma is toxic epidermal necrolysis (Lyell’s syndrome). It occurs with damage to internal organs, the nervous system and characteristic dying away of the epidermal layers of the skin.
Treatment: antihistamines, corticosteroids in tablet, injection form. Obligatory intake of sorbents, plenty of fluids, as well as symptomatic treatment according to the state of the body (support of the cardiovascular system, kidneys, liver).
The role of prevention in the treatment of allergies
Allergies are difficult to cure, so prevention is very important in maintaining health. Basic recommendations:
Eliminate contact with the main irritant. Try to reduce the frequency of contact with potential allergens (citrus fruits, honey, flowering houseplants, cat hair, etc.).
Avoid stress and maintain a healthy psycho-emotional background. Statistics show that stress is often the trigger for allergen sensitization.
Damp-clean regularly – this will reduce the concentration of dust and allergenic microorganisms.
Use hypoallergenic detergents.
Saline nasopharyngeal lavage at least once a day.
Include in your daily diet fresh fish and some spices – mustard, horseradish, turmeric. It has been noted that the substances they contain help eliminate allergens from the body. It is useful to buy Omega-3 supplements and folic acid, as they give the body extra protection against hypersensitization.
Breastfeeding is the most effective allergy prevention for young children.
Studies show that severe allergies are typical only for residents of large cities. Living in the countryside in close contact with nature, minimal stress and proper nutrition, a person gets rid of most of the pathological immune reactions.