Allergy.Diagnosis of allergy

immune disorders often lead to the fact that humans develop harmful allergic reactions, ranging from a simple runny nose, red eyes and hives to chronic digestive disorders, atopic dermatitis, severe bronchial asthma.The basis of the vast majority of allergic diseases is a disorder of the immune system of an individual and the response to various irritants (allergens), leading to excessive production of antibodies.The interaction of antibodies and allergen develops a chain of reactions that lead to inflammation and tissue damage.

External allergy depend on which organ is involved in the inflammatory process, and how the symptoms of inflammation are expressed.Not identifying and removing the allergen is impossible to achieve successful treatment of allergic disease.Therefore, the first and most important step in treating allergies is to identify the allergen.

Skin tests

Skin tests - introduction into the skin of the forearm or the back of small amounts of purified allergens in certain concentrations

.There are three methods of carrying out such tests.

scratch test in which a doctor performs surface scratching (scarification) of the upper layer of the skin with the introduction of an allergen into this area.

Intradermal test, in which the allergen is injected using a syringe with a very fine needle.

Agulhas test (skin prick test), in which the skin is applied a drop of allergen, and then beneath this drop is a thin needle prick the skin.

These samples are used in a variety of allergens dilutions.In all three cases, the reaction results can be evaluated after 20-30 minutes.The sample is considered positive if the observed formation of papules, erythema (redness), or a rash.Contrary to popular belief skin tests can be performed at any age.

blood test

To diagnose an allergy is defined as the highest value in the blood concentrations of immunoglobulin E. The increased amount of protein favors the production of specific antibodies by the body against environmental allergens.Determination of IgE in serum is carried out, withdrawn from a vein in the patient.The method is based on a mixture of purified allergens in the presence of IgE class antibodies that bind to them and form complexes antigen (allergen) - antibody.Thinner laboratory tests can detect the type of reaction and determine its urgency.To test the use of more than 200 allergens.Its special feature is that the patient does not need to come into direct contact with the allergen.The risk caused by this is excluded.Is defined as total and allergen-specific IgE.

Provocative tests

principle of these tests is to reproduce the symptoms of an allergic reaction after contact with the allergen.If an allergic reaction develops in response to the alleged allergen, the allergen may be considered a cause-significant (specific).

provocative inhalation test.To provoke acute asthma patient in turn is administered via the lungs all possible allergens or use exercise, cold and so on. D.

similar principle is also used to induce allergic rhinitis (nasal provocation test) or food allergy (oral provocation test).

Provocative tests are used only when there are differences between the medical history, the results of skin tests and the data of biochemical studies (IgE and so on. D.) They are performed in specialized centers, since interpretation of the data requires specialized knowledge, and they are not indifferent to the patient.For example, it may be an exacerbation of asthma.

These tests are also used to identify the severity of the allergy and determine the effectiveness of drug therapy.

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