The Man of a Thousand Pustules: A Case About Acute Generalized Exanthematous Pustulosis

Acute generalized exanthematous pustulosis (AGEP) is a rare entity characterized by fever associated with the sudden appearance of erythematous lesions, on which multiple sterile, non-follicular pustules develop. We describe a case of a 44-year-old healthy male who developed fever and multiple erythematous and edematous lesions with progressive generalization to the entire body, associated with multiple small non-follicular pustules three days after having started flucloxacillin for the treatment of a furuncle. Considering the characteristics of the exanthema, fever, and association with aminopenicillin initiation, AGEP was considered. A skin biopsy revealed subcorneal and superficial epidermal pustules, with foci of spongiosis, papillary edema, and a superficial, perivascular inflammatory cell infiltrate with neutrophils and eosinophils, consistent with the clinical diagnosis of AGEP. The culprit drug was suspended, and prednisolone was started, considering the rash extension, with progressive and complete improvement. Although it is a rare condition, the hypothesis of AGEP should be considered in acute febrile conditions with disseminated pustules. It resolves spontaneously after discontinuation of the offending drug, and the diagnosis is based on clinical presentation and skin biopsy.