Pyoderma gangrenosum and systemic lupus erythematosus: a report of five cases and review of the literature.

Pyoderma gangrenosum (PG) is an uncommon, distinctive cutaneous ulceration which is usually idiopathic, but may be associated with many systemic disorders. The etiopathogenesis of PG is still not well understood. PG is part of the spectrum of the neutrophilic dermatoses and it has been proposed as a prototype of cutaneous autoinflammatory disease. PG usually has a good outcome under immunosuppressive treatment. Although PG has been associated with several systemic diseases, it has rarely been reported in association with systemic lupus erythematosus (SLE). In this article we report five cases of SLE-related PG and review the literature. Our findings support the possible relationship between active SLE and PG, although the mechanism remains unclear. Clinical manifestations, used treatments and outcomes of SLE-related PG do not differ from the described for the general population.