What is Allergy?

Filed in archive About on February 24, 2010

© Cyron

It is an abnormal reaction by immune system of a person against harmless substance. Allergy is also referred to as atopy. It is one of the four forms of hypersensitivity and is known as type I hypersensitivity. Allergy leads to activation of mast cells and basophils which leads to inflammatory response. Some of the common allergic reactions are food allergies, asthma attacks, hives, eczema and hay fever. Allergies are caused as a result of dust or pollen which are airborne particles and symptoms occur when some body areas come in contact with air such as nose, eyes and lungs.

Clemens von Pirquet, a Viennese pediatrician introduced the concept of allergy after he noticed that his patients were hypersensitive to pollen, dust and certain kinds of food. The risk factors of allergy can be divided into two classes - environmental and host factors. Environmental factors include allergen levels, environmental pollution and dietary changes whereas host factors include age, heredity, race and sex. The medical field dealing with allergies is known as allergology.