Montelukast in allergic diseases beyond asthma.

Allergic diseases include a variety of different illnesses (rhinitis, conjunctivitis, asthma, urticaria, and dermatitis) in which the physiological and pathological basis is the release of chemical mediators such as histamine; platelet-activating factor; metabolites of arachidonic acid; and chemotactic factors from mastocytes, basophils, and eosinophils. The numerous drugs used for allergy treatment now include the new pharmacologic category of cysteinyl leukotriene (LT) antagonists. LTs are released from eosinophils, mast cells, and macrophages, interacting functionally in allergic reactions against a background of an imbalance between T-cell clones and resulting in preferential cytokine production following the T-helper 2 profile. Anti-LTs also have been used successfully by some authors to control rhinitis, atopic dermatitis, and urticaria. although additional controlled testing will be required, these applications broaden the possible range of treatments for allergic disease in all its many aspects.