Comparative efficacy of topical antipsoriatic treatments, systemic treatment and biologics: is severity assessment beyond Psoriasis Area and Severity Index a necessity?

Abstract

Conflicts of interest: none declared. Sir, A retrospective analysis recently appeared in the International Journal of Dermatology summarizing data from six multicentre studies including 2452 patients on the efficacy and safety of the two‐compound product calcipotriol/betamethasone dipropionate ointment.1 In 54·1% of these patients with moderate to severe psoriasis a reduction of the Psoriasis Area and Severity Index (PASI) of at least 75% (PASI 75) was already reached after 4 weeks. When this result is compared with PASI 75 data of biologic treatments after 12 weeks, only infliximab was found to be as effective as the two‐compound topical product. This message challenges the common belief that the efficacy of a topical treatment is inferior to that of systemic treatments. However, we felt that some critical notes have to be made with respect to the design of comparative analyses between populations eligible for topical treatment, systemic treatment and biologics and, furthermore, with respect to the use of PASI as sole outcome criterion to assess severity of psoriasis symptoms at baseline and efficacy of treatments.