Acute generalized exanthematous pustulosis

PURPOSE OF REVIEW: The purpose of the present review is to update knowledge on acute generalized exanthematous pustulosis (AGEP) in terms of epidemiology, pathogenesis, cause, clinical features, diagnosis, and treatment. RECENT FINDINGS: AGEP is a rare reaction pattern attributed mainly to drugs. Drug-specific T cells (CD4 and CD8) and the production of interleukin-8/CXCL8 play an important role in its pathogenesis. A large-scale case-control study (EuroSCAR study) revealed a broad spectrum of drugs strongly associated with AGEP characterized by different time patterns (latent periods). Recent publications have supported the recognized role of individual drugs in the induction of AGEP and some have reported newly incriminated drugs. Many recent publications on AGEP have used the AGEP validation score (EuroSCAR group criteria) to establish the diagnosis. The value of in-vivo tests (mainly patch tests), in-vitro tests (the lymphocyte transformation test and cytokine release tests), or both for the identification of causative drugs has been demonstrated. Infections do not play a prominent role in the development of AGEP. There is no evidence for the assumption that AGEP is a variant of pustular psoriasis. Unique observations related to AGEP include a marked female predominance, a possible role for seasonality and a causal role for spider bites. SUMMARY: A broad spectrum of drugs is associated with AGEP, a T cell-mediated reaction. Genetic susceptibility and the possible role of other risk factors in AGEP should be further evaluated in larger studies of AGEP patients with a validated diagnosis.