Generalized Pustular Psoriasis: A Review of the Pathophysiology, Clinical Manifestations, Diagnosis, and Treatment

Generalized pustular psoriasis (GPP) is a rare severe variant of psoriasis that is characterized by the abrupt widespread onset of small pustules accompanied by systemic manifestations of inflammation. It can arise in patients with a history of psoriasis as well as in those without, sometimes due to medication initiation or withdrawal, pregnancy, or infection. Generalized pustular psoriasis is thought to be driven primarily by innate immunity and unrestrained IL-36 cytokine activity. Recent genetic analyses have identified 3 genetic mutations that are associated with GPP-IL36RN, CARD14, and AP1S3-though these mutations only account for a minority of cases. There are many cutaneous pustular diseases that must be ruled out in the evaluation of a patient with suspected GPP, especially acute generalized exanthematous pustulosis (AGEP), and histologic analysis is the cornerstone of diagnosis. Although the quality of evidence to generate treatment recommendations for GPP is limited, management often includes utilization of systemic agents and/or biologics, usually with adjunctive topical treatment. Accumulating evidence suggests that biologic agents, especially infliximab, may be considered as first-line treatment of GPP, especially in severe acute cases, due to their abrupt onset of action and favorable side-effect profiles compared with oral systemic agents.