An allergy is an overreaction of the immune system to particular substances foreign to the body. These substances, also known as allergens, enter the body through the skin, the digestive tract or the respiratory tract. They start an allergic reaction that can cause nasty symptoms. Allergy is the most common chronic disease.


In the event of an allergic reaction, an allergen activates the immune system. This system recognizes the allergen as ‘enemy’, wants to disarm it and produces particular proteins, called antibodies. As a consequence, a series of reactions is initiated, in which strong chemical substances, such as histamine, are released. Not the allergens themselves, but these chemicals cause allergic symptoms. An allergic reaction can occur immediately (within a few minutes to several hours) or delayed (after a few days).
Why a person gets an allergic reaction is often not clear. Allergies are not contagious, but there may be a genetic predisposition. The more family members have allergies, the greater the chance that a child develops an allergy too.


Different allergens provoke different symptoms. There are three types of symptoms:

A very severe allergic reaction is called anaphylaxis or anaphylactic shock. This can occur, for example, after a wasp sting. As a result, the tongue, lips and eyelids can swell with (serious) chest tightness, because moisture can get into the lungs. This complication can be fatal and requires immediate medical intervention.


Based on the symptoms, the course of the symptoms and physical examination, the diagnosis of allergy is sometimes immediately clear. In addition, more investigation can be done in the form of an allergy test to see exactly which allergens cause the allergic reaction:

Allergy can also be determined by testing for a type of protein in the blood, called IgE.


When an allergy is identified, it can be treated in several ways:


The prospects are associated with the type of allergic reaction, the type of allergen, the severity of the condition and the age at which the allergy has begun. Allergic reactions that often occur in young children, such as milk proteins allergy, may decrease as the child grows older. Part of the patients, however, suffer a lifelong allergic condition. Allergic reactions that occur later in life, usually remain.