Systematic review: IBD-associated pyoderma gangrenosum in the biologic era, the response to therapy

Background Pyoderma gangrenosum (PG) in inflammatory bowel disease (IBD) is uncommon and therapeutically challenging. Its treatment remains poorly characterised due to limited individual centre or practitioner experience. No large series are reported since 2003, yet IBD treatment has changed substantially. Aim To provide an up-to-date review of the published treatment efficacy of currently available therapies for IBD-related PG in the biologic era. Methods Systematic review of cases published post-2003 since the broad availability of anti-tumour necrosis factor-alpha (TNF) therapy. Cases which did not have coexistent IBD, were non-English language, of paediatric age or without data on response to therapy were excluded. Results Sixty cases were identified; 55% female, 50% UC, 45% CD, 5% IBD-U. At PG diagnosis, 58% had active and only 15% inactive IBD, with 27% with IBD activity unspecified. Predominant sites were lower limb (48%) and peristomally (25%); 42% had multiple lesions. In 12%, trauma preceded PG. In 42%, new PG appeared whilst on IBD-specific therapy, whilst 28% were on no therapy and in 30%, IBD therapy was unspecified. Of patients on no therapy at PG onset (n=17), 16 healed; seven with first- and eight with second-line therapy. In total, 34/60 patients received infliximab, four received adalimumab, two had both; with 33 (92%) responding to one or the other. There was no correlation of PG duration or size with healing times. Conclusions Pyoderma gangrenosum appears predominantly during active IBD and is seen equally in CD and UC. New PG may be a manifestation of recrudescent IBD or it follow trauma. Anti-TNF therapy as a first-line agent for PG should be considered, as it appears to be highly effective.