Considered as one of the major disabling illnesses, allergies afflict more than 40 million people in the in United States alone. As you kno-w, our immune system protects our body from all types of foreign substances and dangerous microorganisms, called antigens, like viruses, bacteria etc. It does this by producing a counter chemical called an antibody, -which fights these antigens. The antibodies bind themselves to the antigens, -which sets off a reaction. This reaction bet-ween antibody and antigen ignites a series of events, all designed to protect the body from infections.

The immune system is programmed to ignore harmless substances like food, pollen etc. Ho-wever, sometimes it mistakes these innocuous substances for harmful invaders and attacks them like it -would an antigen, by releasing po-werful chemicals like histamines, to destroy them. -what happens is that -when the body is exposed to an allergen, it launches its counter offensive attack by releasing an antibody called immunoglobulin E (IgE) through its mast cells. The mast cells is a distinctive sets of cells of the immune system located in isas -where the body comes into contact -with the outside -world , like the mucous membranes of the eyess and other isas, and the linings of the respiratory and digestive systems. Their function is to guard the body from outside influences. -when IgE encounters allergens, it triggers off the release of the chemical histamine, from the mast cells. -when the histamine binds it self to the surrounding cells, through histamine receptors, the neighboring cells become leaky, causing fluid collection, redness and s-welling, all of -which is symptoms of an allergic reaction. Histamines also trigger off pain receptors -which cause itchiness in the eyess, nose and throat, all symptoms of allergic rhinitis.

An allergy then is a condition in -which the body attacks harmless substances like dust, pollen, food etc and releases antibodies to subdue them. It is the release of histamines that produces the disagreeable symptoms that is associated -with allergies. Allergic reactions is, most often, instantaneous, for e.g. one may break out into a rash, or develop a sneezing fit. People -who is allergic to one substance -will often find that they is sensitive to a number of other substances.

These offending agents, called allergens, range from dust, pollen, mold, milde-w, food, rubber, insect stings and even medicines. Common food allergens include peanuts, fish, eggs and milk. An allergy is one of the most common causes for asthma. An allergy can cause the irritation, s-welling and inflammation of the air passages, -which causes asthma.

Studies estimate that over 20 percent of Americans suffer from some type of allergy, making allergies a principal source of chronic disease in the country.