Analysis for allergy: indications and norm

An allergy test is a necessary test to help identify an antigen that provokes an allergic reaction and begin timely treatment. Moreover, it is almost impossible to achieve the result and really stop the allergy, if not to clarify the etiology of the disease and the actual allergen. The diagnostic method involves the taking of skin tests "in vivo", as well as the "in vitro" method, which studies the antibodies of the blood. This is allergic tests and the detection of IgE in the blood, the main substance responsible for the aggressive reaction of the immune system to the allergic antigen.

Allergoproby - are prescribed mainly with pollinosis, as well as with atopic dermatitis, allergies to medicines, food allergies, rhinitis and sinusitis of allergic etiology, less often with bronchial asthma and pneumonia. It is not recommended to conduct allergic tests for severe infectious diseases, tuberculosis, allergy exacerbations, in cases of hormone therapy, do not conduct allergic tests to pregnant women and in case of a general severe condition of the patient.

[1], [2], [3], [4]

Dermal (skin test)

Dermal (skin tests) are conventionally divided into direct and indirect. Direct skin tests involve the introduction of an antigen (allergen) under the skin or on the skin, an indirect method is the introduction of serum containing IgE, and then the introduction of the antigen. Technically, samples also have variants - they are made by a drop method, by a scarification method, by an application method or by a prick test. Method, the method directly depends on the form of the allergic disease, the degree of sensitivity of the proposed reaction. All this information gives a pre-collected history. The analysis for allergy in the form of allergens is based on a possible response to the administration of the putative allergen. Depending on the reaction - immediate or delayed, you can detect the result within 30 minutes or 8 hours. After 20-30 minutes, an immediate reaction is determined for the area of hyperemia on the methotrex, and also for the blister. If the samples are taken for household or food allergens, then the information should wait up to eight hours, and sometimes even a day. Allergic tests are examined in bright enough light, a positive test is considered if the papule reaches 2 mm.

One procedure can include up to 20 samples for different allergens. In order to ensure that the results of allergic tests are not distorted, the patient should exclude the use of antihistamines.

[5], [6], [7], [8], [9], [10]

Allergy test by IgE immunoglobulin assay

An antibody called IgE is responsible for all allergic reactions. IgE immunoglobulin functions in serum for no more than three days, about two weeks in the membranes of basophils and mast cells. This antibody has the property of being fixed on the cells of the mucous membrane, on the skin, so blood is not his favorite place of dislocation. Any increase in IgE levels in plasma may indicate some form of allergic reaction. The immunogram in children is more informative than in adults. However, this method of analytical research for allergy is quite effective and is actively used all over the world. The test is still good and the fact that a person does not need to contact directly with the allergen, as in the case of an allergic test. In addition, the test has no contraindications, it is suitable even for severe, acute forms of allergic disease.

Indications in which the IgE assay is performed: 

• All forms and types of allergies; 
• Assessment of the risk of allergy in the case of a hereditary history; 
• Infection with helminths.

An allergy test using IgE antibody testing requires compliance with certain rules, among which are: 

• Exclusion of any physical exertion and emotional stress; 
• The procedure is performed on an empty stomach; 
• On the eve of the procedure, during the day it is advisable to maintain a gentle diet, exclude alcoholic beverages, strong coffee and tea.

IgE rates depend on age and should correspond to such indicators:

• Children up to 1 year - 0-15 units / ml;
• Children from 1 year to 6 years - 0-60 units / ml;
• Children from 6 years to 10 years - 0-90 units / ml;
• Children from 10 years to 16 years - 0-200 units / ml;
• Adults - 0-200 units / ml.

Any increase in the norm limits indicates an active response of IgE immunoglobulin to the invasion of an antigen or infection.

The analysis shows the reaction of immunoglobulin to almost all food antigens, there are about 90 names on the list. The result is such variants of indicators: 

• Negative - up to 50 units / ml; 
• Weak sensitivity + 50-100 units / ml; 
• Moderate sensitivity ++ 100-200 units / ml; 
• High sensitivity +++ more than 200 units / ml.

Analysis for allergy - skin tests or immunological examination, both methods are necessary and important in order to detect the allergen in time and determine the therapeutic actions, appointments, and analysis are used as a testing of the body's reaction to the use of various types of medications to determine their effectiveness.

[11], [12], [13], [14], [15]