TITLE:
Adalimumab-Associated Acute Generalized Exanthematous Pustulosis with Psoriasiform Features: A Diagnostic Challenge
AUTHORS:
María Paula Chimbi-Bru, Karen Sofia Osorio-Contreras, Lucia Vanegas-Torres, Verónica Orozco-Pérez, Katherine Figueroa-Trujillo, Anthony Salazar-Arrieta, Laura Lopez-Rincón, Mariana Vargas-Torres, Juanita Salazar-Castillo, Lorena Molinares-Diaz, Nicole Young-Del Castillo
KEYWORDS:
Acute Generalized Exanthematous Pustulosis, Adalimumab, Anti-TNF Therapy, Drug-Induced Skin Eruption, Paradoxical Psoriasis, Pustular Dermatoses
JOURNAL NAME:
Journal of Biosciences and Medicines,
Vol.14 No.3,
March
20,
2026
ABSTRACT: Background: Acute generalized exanthematous pustulosis (AGEP) is a rare, severe cutaneous adverse reaction, most commonly induced by drugs. It is characterized by the abrupt onset of numerous sterile, non-follicular pustules on an erythematous background and is typically self-limited after withdrawal of the offending agent. Although antibiotics are the most frequent triggers, biologic therapies, including anti-tumor necrosis factor (TNF) agents, have increasingly been implicated. Distinguishing AGEP from pustular psoriasis or paradoxical psoriasis induced by anti-TNF therapy may be challenging due to overlapping clinical and histopathological features. Case: We report the case of a 51-year-old woman with rheumatoid arthritis treated with adalimumab and leflunomide, who presented with a 15-day history of generalized pustular eruption accompanied by malaise but no fever. Dermatological examination revealed widespread erythematous papules and pustules involving the trunk, back, extremities, and prominently the palms and soles, with marked involvement of the axillary folds. A punch biopsy from a dorsal lesion demonstrated histopathological findings consistent with acute generalized exanthematous pustulosis. Laboratory evaluation was unremarkable. Adalimumab was discontinued, and systemic cyclosporine was initiated, leading to complete resolution of the pustular eruption. During follow-up, the patient developed new psoriasiform lesions affecting the scalp and plantar surfaces, raising the possibility of a clinical overlap between AGEP and paradoxical psoriasis secondary to anti-TNF therapy. Conclusion: This case highlights AGEP as a potential severe cutaneous adverse reaction to adalimumab and underscores the diagnostic complexity when psoriasiform features emerge during follow-up. Careful clinicopathological correlation and longitudinal assessment are essential to differentiate AGEP from paradoxical psoriasis, particularly in patients receiving biologic agents. Early recognition and prompt withdrawal of the causative drug remain the cornerstone of management.