New perspectives in allergic asthma.

Major advances have recently been made in both the diagnosis and the treatment of allergic asthma. The radioallergosorbent test (RAST), which measures allergen specificity of lgE antibodies in vitro, offers as good results as direct skin tests for allergy, without the inconvenience, discomfort and risk for the patient of the latter. However, the RAST must be done in a radioisotope laboratory, and standardized extracts of test allergens are lacking. Several new drugs, administered by inhalation and relatively free from serious side effects, are highly effective in treating asthma. Disodium cromoglycate, believed to stabilize tissue mast cells, protects particularly against exercise- or antigen-induced bronchospasm, and often permits reduction or withdrawal of corticosteroid therapy. Some acetonides or esters of glucocorticoids, because of their greatly increased topical anti-inflammatory activity, are effective in doses too small to cause serious systemic side effects. With the most topically effective, beclomethasone dipropionate, systemic corticosteroid therapy can usually be reduced or withdrawn, but recovery of hypothalamic-pituitary-adrenal function may be delayed; the drug regimens should therefore overlap.