What is allergy, its signs and how to recognize allergy

The immune system is the body’s protective mechanism that fights with external aggressors (bacteria and viruses). The immune system of allergists perceives some alien substances as allergens and inserts the protective mechanism, starting to produce antibodies (immunoglobulin E). For each body, allergens are unique, so people suffer from allergies from different triggers - drugs, foods, poultry, etc.