Allergic Disorders

Allergic Disorders

There are two types of IgE-mediated allergic reactions: atopic and nonatopic disorders. While the underlying immunologic re-actions of the two types of disorders are the same, predisposing factors and manifestations are different. The atopic disorders are characterized by a hereditary predisposition and production of a local reaction to IgE antibodies produced in response to com-mon environmental allergens (Kay, 2001a). The nonatopic dis-orders lack the genetic component and organ specificity of the atopic disorders (Porth, 2002). Examples of atopic disorders are allergic rhinitis, allergic asthma, and atopic dermatitis (Kay, 2001a).

A type I hypersensitivity response results in atopic (allergic) dis-eases, which affect 10% to 20% of the U.S. population. Genetic factors play a role in susceptibility to these diseases. Disorders char-acterized as atopic include anaphylaxis, allergic rhinoconjunctivi-tis, atopic dermatitis, urticaria and angioedema, gastrointestinal allergy, and asthma. Latex allergy may be a type I or type IV hyper-sensitivity reaction, although true latex allergy is considered to be a type I hypersensitivity reaction (Brehler & Kütting, 2001). Contact dermatitis is con-sidered a type IV hypersensitivity reaction.