Allergy

A condition in which the immune system reacts abnormally to a foreign substance.

Allergies stem from an inappropriate reaction of the immune system to certain proteins. These proteins are known as allergens, and they are usually common and harmless substances such as pollen, mold spores, animal dander, dust, various foods, insect venoms, or medicines.The immune system is designed to identify intruders within the body and get rid of them. For an allergic person, however, the immune system has a hard time identifying which are the dangerous intruders, and which are okay. An allergic person has a hypersensitive immune system, which singles out a harmless substance (like the allergens mentioned above), then attacks it.

The type of symptoms an allergy sufferer shows depend on the type of allergen. Respiratory allergens cause symptoms like sneezing, sniffling, wheezing, coughing, runny nose, itchy eyes, sore throats, etc. Skin irritants can cause eczema, hives, or other reactions. Responses to food allergens vary greatly, and in severe cases can cause a possibly fatal condition, called anaphylaxis.

Everyone has antibodies, the agents of the immune system which fight various kinds of intruders. The antibody which causes an allergic response is called IgE. In an allergic person, the immune system's IgE can't tell the difference between threatening and non-threatening protein substances.

The first time you are exposed to a specific allergen, your body produces large amounts of IgE antibodies to work against that allergen. The antibodies attach themselves to the cells containing histamine. After repeated exposure to the allergen, eventually the histamine will be released in powerful amounts, causing an onslaught of allergy symptoms. While histamine is an important chemical in the body, it can cause problems if it is released in the wrong situation. Allergy symptoms are the body's attempt to expel a substance it perceives to be dangerous.

There are three methods of treatment for allergies: avoidance, medication, and immunotherapy.

With any allergy, your first method of treatment should be to avoid the offending allergen. This may seem obvious, but with some allergens, it's easier said than done. For the most part it's easy to avoid eating a food to which you are allergic, but more ubiquitous airborne allergens like pollen or dust can seem nearly impossible to avoid. Of course, you can't get rid of environmental allergens completely, but there are a number of things you can do to significantly reduce your exposure to allergens.