The primary allergic diseases include allergic asthma,allergic rhinitis, atopic dermatitis, anaphylaxis, and food hypersensitivities .
Asthma is a disease of the lungs in which the bronchial mucous membrane is chronically irritated and inflamed. This inflammation makes the airways more hyperreac-tive to a variety of provocative stimuli, including allergens, cold air, exercise, and viral infections, leading to bron-chospasm. Typical symptoms include wheezing, chest tightness, cough, and shortness of breath, which may occur episodically or continuously. The disease is diag-nosed by history, findings on examination, and pul-monary function testing.
Allergic rhinitis (to be discussed in greater depth later) is similar to asthma, in that it represents mucosal inflam-mation of the nose. The most common symptoms are nasal congestion, sneezing, itching, and discharge. The diagnosis of rhinitis is based primarily upon the history and physical examination.
Atopic dermatitis is an eczematous skin disease that usually begins in infancy and is characterized by red-ness, itching, and allergic eczema . It most commonly affects the flexural areas of the arms and legs.
Anaphylaxis is a life-threatening condition in which a systemically administered allergen, such as a food, drug, or insect sting triggers the rapid and massive release of mast cell mediators throughout the body. The ensuing reaction may involve the skin, airways (including nose, larynx, and lungs), gastrointestinal tract, and systemic circulation, with symptoms of flushing, hives, wheezing, throat swelling, dizziness, or even loss of consciousness.
Food hypersensitivity includes a variety of hypersensi-tivity reactions, most commonly including IgE-mediated anaphylaxis and aggravations of atopic dermatitis.
Prostaglandin
A family of lipid mol-ecules derived from arachidonic acid whose effects include tissue inflammation.
Asthma
Disease of the lungs in which the bronchial mucous membrane is chronically irritated and inflamed. The hallmarks of this dis-ease include episodic, reversible spasm of the airways in response to both spe-cific (e.g., allergens) and nonspecific (e.g., cold air) triggers.
Allergic rhinitis
Mucosal inflammation of the nose due to an allergic reaction.