Acute generalized exanthematous pustulosis (AGEP) is a rare, acute, severe cutaneous adverse reaction mainly attributed to drugs, although other triggers, including infections, vaccinations, ingestion of various substances, and spider bites, have also been described. AGEP is characterized by the development of edema and erythema followed by the eruption of multiple punctate, non-follicular, sterile pustules and subsequent desquamation. AGEP typically has a rapid onset and prompt resolution within a few weeks. The differential diagnoses for AGEP are broad and include infectious, inflammatory, and drug-induced etiologies. Diagnosis of AGEP depends on both clinical and histologic criteria, as cases of overlap with other disease processes have been reported. Management includes removal of the offending drug or treatment of the underlying cause, if necessary, and supportive care, as AGEP is a self-limited disease. This review aims to provide an overview and update on the epidemiology, pathogenesis, reported precipitating factors, differentials, diagnosis, and management of AGEP.