Treatment options for pyoderma gangrenosum.

Pyoderma gangrenosum (PG) is an orphan disease. While research on such disorders is based on only few randomized multicenter as well as retrospective studies, most of the data comes from case series of small patient groups. Apart from topical and intralesional therapeutic options for early stages and mild disease courses, treatment predominantly involves systemic therapeutic agents. Besides systemic corticosteroids and cyclosporine A (CsA), options also include intravenous immunoglobulins (IVIG) and biologics such as the TNFα inhibitors infliximab, adalimumab, and etanercept; the interleukin (IL) 12/23 antibody ustekinumab; the IL-1 receptor antagonist anakinra; and the IL-1β antibody canakinumab. The best evidence-based study data is available for CsA, prednisolone, and infliximab; the latter especially in patients with concomitant ulcerative colitis or Crohn's disease. A response to IVIG and canakinumab has been reported in smaller case series. First described by Brocq almost 100 years ago, it was soon recognized that PG did in fact require treatment. To this day, however, such treatment remains a clinical challenge. Despite the severe - albeit rare -clinical picture, improvement in therapeutic options may be expected in the future, primarily due to further clinical studies - especially with a greater number of patients, a better understanding of the etiopathogenesis, as well as the use of modern targeted therapies with higher efficacy and a lower rate of side effects than conventional immunosuppressants such as prednisolone and CsA.