Allergy - an acute response of the immune system of the body to normally harmless substances. Allergies can occur at the wool of some animal species, a variety of foods, dust, drugs, chemicals, insect stings and pollens. Substances that cause an allergy, called allergens. In some cases, allergic reactions occur so slowly that you may not even know that in general suffer from allergies. But allergies can be, on the contrary, it is extremely dangerous and even life threatening. In people suffering from allergies, anaphylactic shock may occur serious pathological condition associated with extremely sharp reaction to the allergen. Anaphylaxis can be caused by various allergens: drugs, insect bites, food. Also anaphylactic shock can occur due to skin contact with an allergen, such as latex. Food allergy is an immune reaction caused by certain foods and is accompanied by well-known symptoms. Generic Allegra online A food allergy occurs when the body mistakenly thinks is a product of a threat to health and the self-defense forces the immune system to produce antibodies. Repeated dose allergen immune system already knows this stuff quickly and immediately reacts by producing antibodies again. These substances and cause allergic symptoms. Food allergies are almost always develops in this way.