ABSTRACT
Allergy is the exaggerated response of the immune system to foreign proteins such as environmental allergens including mold, pollen, and other allergens (Blumenthal and Rosenberg 1999). The allergic conditions most frequently recognized are allergic rhinitis, conjunctivitis, and bronchial asthma. The immune response in atopy results from the interaction of the host with an allergen and other modulating environmental factors. Not all individuals develop allergy even after extensive exposure to allergens suggesting a role for genetic predisposition in hypersensitivity diseases. Allergen has been defined as the substance that is involved in atopy, an adverse immune reaction resulting from the induction of specific Immunoglobulin E (IgE). Exposure to allergens can be by inhalation, contact, ingestion, and by injection. The response to an allergen is determined by its structure and nature, host factors such as genetical, predisposition and underlying diseases, and environmental factors, including pollution and high levels of allergen concentrations.
