Lenalidomide and Dexamethasone in Scleromyxedema: A Case Report of Long-Term Efficacy and Challenges in a 54-Year-Old Patient.

Lichen myxedematosus (LM) is characterized by dermal mucin buildup, fibroblast proliferation, and variable presentation. The diffuse variant, known as scleromyxedema, is identified by monoclonal paraprotein presence and lack of thyroid issues, with considerations for infections and underlying conditions. Despite lacking FDA-approved treatment, intravenous immunoglobulin stands as effective, although resource-intensive, while targeting the clonal source of pathogenic immunoglobulin offers an alternate therapeutic route. Our case explores the efficacy of an oral plasma cell-focused lenalidomide regimen, inducing relief and treatment-free periods, while still facing relapses. However, this approach poses risks, necessitating a comparative safety and efficacy assessment. Data remains insufficient to establish the prolonged efficacy of plasma cell-targeted therapy versus alternatives for monoclonal gammopathy of undetermined significance-associated scleromyxedema. We present the case of a 54-year-old male patient diagnosed with LM managed for six years with relapsing and remitting symptoms.