Pustular Psoriasis and Associated Musculoskeletal Disorders.

Pustular psoriasis (PsO) is an uncommon variant of PsO that may present in a generalized or localized fashion with or without musculoskeletal or systemic inflammatory involvement. Generalized pustular PsO (GPP) presents as a widespread acute or subacute pustular eruption that may be familial and is often associated with severe flares and systemic inflammation. The palmoplantar pustulosis variant is localized to palms and soles, whereas acrodermatitis continua of Hallopeau is localized to the nail apparatus. Patients with pustular PsO may have overlapping plaque PsO and may develop psoriatic arthritis (PsA). Pustulosis is also a feature of both synovitis, acne, pustulosis, hyperostosis, osteomyelitis (SAPHO) syndrome and chronic nonbacterial osteomyelitis. At the 2020 Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) annual meeting, members were given an overview of the cutaneous features of pustular PsO, SAPHO, and recent insights into the genetics of GPP, leading to new targeted drug therapies and the development of validated endpoints.