From the Research
Diagnosing Acute Generalized Exanthematous Pustulosis (AGEP) requires a comprehensive approach combining clinical evaluation, laboratory tests, and histopathology, with the most recent and highest quality study suggesting that diagnosis depends on both clinical and histologic criteria 1. The diagnosis begins with recognizing the characteristic widespread, non-follicular sterile pustules on an erythematous base that typically appear rapidly, often within 24-48 hours of exposure to the causative agent. Some key points to consider in the diagnosis of AGEP include:
- Laboratory findings typically include leukocytosis with neutrophilia, mild eosinophilia, and elevated inflammatory markers such as C-reactive protein.
- A skin biopsy is crucial for confirmation, showing subcorneal or intraepidermal pustules, spongiosis, papillary dermal edema, perivascular infiltrates with neutrophils and eosinophils, and occasional leukocytoclastic vasculitis.
- The EuroSCAR scoring system can help differentiate AGEP from other pustular conditions, considering factors like morphology, distribution, course of pustules, history of drug exposure, and histopathology.
- Identifying and discontinuing the causative medication is essential, with antibiotics (particularly beta-lactams), calcium channel blockers, antimalarials, and terbinafine being common triggers, as reported in recent studies 2. Patch testing may be performed later to confirm the specific causative agent, though this is not necessary for immediate management, and recent experimental data suggest an early role of drug-induced innate immune activation and innate cytokines such as interleukin (IL)-1, IL-36, and IL-17 in the pathogenesis of AGEP 2.