What is an allergy? The very word “allergy” comes from the combination of two words in Greek: allos – other and ergon – work and means an inappropriate reaction of the body’s immune system when exposed to substances that cause it. This reaction is acquired, and the body of an allergic person (also known as hypersensitivity) at the time of contact with the sensitizing substance responds with a number of symptoms from the following:
- runny nose
- stuffy nose
- bouts of sneezing
- shortness of breath
- frequent, recurrent bronchitis,
- cough not accompanied by an acute infection,
- conjunctivitis,
- itchy skin lesions,
- recurrent upper respiratory infections.
The symptoms listed above may indicate the development of allergies in our body, and each subsequent exposure to a sensitizing substance (allergen) will strengthen the immune reaction. Allergens are usually proteins found around us, they stimulate our own IgE antibodies (which should properly defend our body against parasites) other cells in the body (basophils and mast cells) to secrete, among others, histamine (i.e. substances that promote inflammation), which causes the listed reactions. If you notice the above-mentioned symptoms, you should visit a doctor who, after excluding other disease factors, will recommend allergy tests.
We include basic allergy tests skin testse.g. puncture, which consists in the application by a nurse or other qualified person to the skin surface (usually the forearm) at set intervals of a small amount of allergens, mainly inhalants (trees, grasses, cereals, pets, grass and cereal pollen and house dust mites ) and histamine solution (positive control) and saline (negative control), and then piercing the epidermis to introduce the substance into the dermis area with a 1 mm long blade. The result is read after about 20 minutes and is marked on a five-point scale from 0 (size of reaction to saline solution) to ++++ (meaning the size of a wheal twice the size of a histamine wheal, or a wheal with irregular protrusions – pseudopods).
The second basic type of tests are blood tests used to determine the level of total or specific IgE immunoglobulins. They are performed in people with contraindications to skin tests, e.g. due to severe skin lesions, and in children under 5 years of age. The correct level of IgE depends on age, e.g. for a six-month-old child it is 7,3 kU/l (kilo units per liter of serum), while for a 6-year-old child it is already 56 kU/l. In an allergic person, this level is significantly elevated, however, exceeding the norm does not always mean an allergy, parasitic, bacterial, cancer and autoimmune diseases should be excluded. These tests are safer than skin tests because the allergen is administered outside the body and does not come into contact with the allergic person, but they are less sensitive and more expensive.