Allergic Reactions

Normally, the immune system is the body's defense against invading agents such as bacteria and viruses. In most allergic reactions, however, the immune system is responding to a false alarm. When an allergic person first comes into contact with an allergen, the immune system treats the allergen as an invader and mobilizes to attack. The immune system does this by generating large amounts of one type of antibody. When the allergen and the antibody connect, it signals the release of powerful inflammatory chemicals. These chemicals, like histamines, cytokines, and leukotrienes, act on the tissues of various parts of the body, such as the respiratory system. The result is the symptoms commonly associated with allergies.