Allergic Disease, Allergic Disorders, Allergic Illness

Allergy
Allergic Disease, Allergic Disorders, Allergic Illness

Viennese paediatrician Baron Clemens von Pirquet coined the term "allergy" (from the Greek "allos" meaning changed or altered state and "ergon" meaning reaction or reactivity) in 1906 [ 1 ]. Von Pirquet used the term to describe an altered reaction he had observed in patients, which he put down to the influence of external factors, an allergen , on the immune system.

Allergies are hypersensitivity reactions of the immune system to specific substances called allergens (such as pollen , stings , drugs , or food ) that, in most people, result in no symptoms .

The most severe form of allergy is Anaphylactic shock , which is a medical emergency.

Various types of classifications exist.
Allergy has different names depending upon where in body it occurs.