A reappraisal of topical steroid potency

Topical corticosteroids have been one of the cornerstones of dermatologic treatment for nearly 40 years. At present the most widely used topical steroid ranking system is the vasoconstrictor assay. To determine whether this is a satisfactory measure of the agents' potency in clinical settings, we examined rankings from the published literature achieved by four different methods: vasoconstriction, clinical outcome, therapeutic index (a ratio of efficacy to systemic safety), and cost, safety, and efficacy. Overall clinical outcome (efficacy) rankings in this study corresponded in only 11 (62%) of 17 topical steroid preparations with the expected vasoconstrictor rankings. The therapeutic index rankings did not correspond with the clinical outcome (33%) or the vasoconstrictor assay (33%) rankings. It was difficult to compare studies because of lack of standardization of clinical trials. We urge that topical steroid rankings not be based solely on vasoconstrictor assays, and that a standard method be developed for clinical trials of the drugs to allow for comparison among preparations.