A rare case of keloid combined with bullous pemphigoid.

Keloids and bullous pemphigoid (BP) are two clinically and pathophysiologically distinct dermatologic disorders - the former is characterized by abnormal scar formation due to excessive collagen deposition, whereas the latter is an autoimmune blistering disease. We report a case of a 67-year-old man with a 19-year history of abdominal keloids and the subsequent appearance of vesicular skin lesions. Histopathologic examination revealed both keloidal fibrosis and subepidermal blister formation. Serum testing demonstrated elevated anti-BP180 antibody levels. Initial treatment with topical and systemic agents, including neomycin, glycyrrhizin, spironolactone, and minocycline, resulted in limited improvement. Subsequently, dupilumab - a monoclonal antibody against the interleukin (IL)-4 receptor α - was introduced. After 2 months of dupilumab therapy, the vesicular lesions resolved, keloids stabilized, serum anti-BP180 antibody levels normalized, and the Dermatology Life Quality Index (DLQI) score decreased from 11 to 2.