Although topical steroids are a ubiquitous part of dermatologic care, in recent years, they are rarely a major topic of discussion or investigation. It is telling that the US guidelines for the use of topical corticosteroids1 have not been updated for a quarter century.
In their classification study in this issue of JAMA Dermatology, Bowie et al2 meticulously assessed 3 international potency classification systems for topical steroids for agreement and correlation. The first step the authors undertook was to identify a comprehensive list of topical steroid formulations as found in the Anatomical Therapeutic Chemical (ATC) classification system of the World Health Organization (WHO),3 the Ontario Drug Benefit Formulary,4 a recent Cochrane review on the use of topical steroids in eczema,5 and elsewhere. Bowie et al2 then compared 3 potency systems: (1) the ATC of the WHO3; (2) the US 7-category system; and (3) a system based on the British National Formulary (BNF) and extended in a recent Cochrane review.5 Bowie et al2 found that these 3 classification systems were incongruent, and their sources were not transparent. They urged authors of epidemiological studies to be clear about the potency systems they use. Because of the differences found, the authors go a step further and suggest using more than 1 system for sensitivity analysis.2 This Editorial discusses the concept of steroid potency, compares and contrasts the 3 potency systems evaluated by Bowie et al, and discusses the implications of the findings for clinical practice.