Anti-IL 17 biologics and pyoderma gangrenosum - therapeutic or causal?

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis characterized by pustules that rapidly progress into ulcers that commonly affect the lower limbs. Recently, successful treatment of PG has been reported with anti-IL 17 treatments. However, there have also been several reports of "paradoxical" induction of new PG lesions after use of IL-17 inhibitors. In this narrative review, we present the currently published English literature on cases in which PG has been successfully treated with IL-17 inhibitors and cases of possible newly induced PG after the use of IL-17 inhibitors. After use of the Naranjo Adverse Drug Reaction Probability Scale, it is difficult to conclude an adverse reaction of PG from anti-IL 17 biological agents. Our review also concludes that IL-23 and IL-36 inhibitors can be considered an alternative treatment for PG.