What is an Allergy?

Allergy is a chronic respiratory disease caused by an inappropriate, sudden, undesirable response of the immune system to foreign substances that are usually harmless and don’t provoke illness, such as food, medicines, pollen, insect venom, etc. An allergic reaction occurs when these substances come into contact with various body tissues and generally leads to symptoms in those areas (for example, skin, digestive system, airways, etc.).

How Does an Allergic Reaction Work?

The body’s response to allergens is accompanied by the production of specific antibodies called IgE - Immunoglobulins E. These antibodies activate various immune system cells (mast cells in the first place) and cause them to release certain substances (for example, histamine, leukotrienes, and cytokines), which trigger an allergic reaction. IgE antibodies are particular for each allergen, meaning that some people may, for example, develop an allergy to pollen, while others are allergic to cat hair, milk, eggs, etc. The degree of allergic sensitivity differs across various immunoglobulins, so allergy can manifest itself in different ways: from mild symptoms to serious allergic complications (such as anaphylaxis).