Long-term Remission of Pyoderma Gangrenosum, Acne, and Hidradenitis Suppurativa Syndrome.

Pyoderma gangrenosum (PG), acne, and hidradenitis suppurativa (HS)(PASH) syndrome is an autoinflammatory condition that is poorly characterized in the literature, and achieving extended remission has proven difficult. We report the case of a patient with a history of cystic acne and HS who was referred to dermatology for evaluation of refractory PG of 18 months' duration. After therapeutic refinement, remission was achieved and maintained for 4 years using adalimumab and cyclosporine. Treatment success generally is only achieved using multimodal therapies targeting various molecules of the innate immune system, suggesting that PASH syndrome may involve multiple pathways of the inflammatory cascade; however, current understanding of the disease mechanism is scarce. The distinct genotypic and immunologic abnormalities of PASH syndrome require further study to uncover the mechanisms that therapeutic regimens aim to interrupt. Multimodal therapy is necessary to control the autoinflammatory nature of this disease, and further reports of therapeutic successes are essential for advancement in understanding this debilitating condition.