Sequential Treatment of Generalized Pustular Psoriasis Combined with Bullous Pemphigoid Using Spesolimab and Dupilumab: A Case Report and Literature Review.

Introduction: Generalized pustular psoriasis (GPP) and bullous pemphigoid (BP) are two distinct but occasionally coexisting inflammatory skin disorders. Their simultaneous presence presents diagnostic and therapeutic challenges. Spesolimab and dupilumab are novel biologics targeting the IL-36 and IL-4/IL-13 pathways, respectively. However, their sequential use in treating GPP with BP has not been previously reported. Case Presentation: We report a 58-year-old man with a 10-year history of psoriasis who developed acute GPP followed by BP. Initial acitretin therapy resolved pustules but not bullae. A single dose of intravenous spesolimab led to rapid improvement of systemic symptoms and pustular lesions. Persistent bullae were subsequently treated with dupilumab (600 mg loading dose, then 300 mg biweekly), resulting in complete resolution within 2 months. The patient remained relapse-free for 6 months, with no adverse events. Conclusion: This case highlights the potential of sequential spesolimab and dupilumab therapy as an effective and safe approach for managing GPP coexisting with BP. Targeting distinct inflammatory pathways may provide a new treatment option for complex dermatological comorbidities.