The clinical assessment of topical corticosteroid activity.

Glucocorticoid-induced vasoconstriction of human skin has provided a useful guide to topical anti-inflammatory activity. The concentration and base in which a steroid is used influence this activity, and traditional greasy ointments are probably the most effective vehicles. Confirmation of clinical effectiveness should be by double-blind comparison in patients with bilateral skin lesions. Psoriasis provides a more discriminating test of steroidal activity than eczema; the use of occlusive dressings may mask differences between compounds. Short-term trials are informative but in patients with chronic diseases, longer studies should also be done.