Scleredema Associated With IgG/κ Monoclonal Gammopathy of Clinical Significance Successfully Treated With Daratumumab Monotherapy: A Case Report

Background Cutaneous monoclonal gammopathy of clinical significance (MGCS) is rare and may present with scleredema‐like fibrosing skin disease. Case A 59‐year‐old man developed progressive induration of the upper body. Laboratory studies revealed an IgG/κ monoclonal protein, and skin biopsy showed dermal thickening with mucin deposition. He was refractory to corticosteroids, immunosuppressants, IVIG, plasmapheresis, and bortezomib. Results Daratumumab monotherapy led to rapid improvement after 4–5 cycles, sustained over 20 cycles, with mobility recovery, mRSS reduction, paraprotein disappearance, and partial histologic regression. Conclusion Daratumumab may represent an effective clone‐directed therapy for refractory MGCS‐associated scleredema. Trial Registration : The authors have confirmed clinical trial registration is not needed for this submission