Scleromyxedema: A rare case report

Scleromyxedema (SM), or Arndt–Gottron disease, is a rare variant of lichen myxedematosus commonly associated with monoclonal gammopathy and may involve multiple organ systems. We report the case of a 56-year-old woman with waxy, skin-coloured papules on the face, neck, trunk, and extremities, accompanied by diffuse induration and classic “doughnut” and “Shar Pei” signs. Dermoscopy showed glistening yellowish-white structures. Histopathology with Alcian blue staining demonstrated a busy dermis with mucin deposition and increased fibroblasts, confirming SM. Serum protein electrophoresis revealed an immunoglobulin G monoclonal gammopathy. Treatment with systemic corticosteroids, UVA phototherapy, and methotrexate resulted in early and notable improvement in skin lesions and induration. With no established standard of care and largely anecdotal therapeutic evidence, this response adds useful insight to the limited literature and highlights the potential of simple, resource-efficient regimens. This case emphasizes the importance of thorough evaluation and long-term monitoring due to risks such as dermato-neuro syndrome.