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

## TL;DR

A 59-year-old man with a rare skin condition linked to a specific protein was successfully treated with a drug called daratumumab.

## Contribution

This case report demonstrates that daratumumab monotherapy can effectively treat refractory scleredema associated with monoclonal gammopathy.

## Key findings

- Daratumumab monotherapy led to rapid and sustained improvement in skin induration and mobility.
- Treatment resulted in disappearance of paraprotein and partial histologic regression.
- The patient showed a significant reduction in modified Rodnan skin score (mRSS).

## Abstract

Cutaneous monoclonal gammopathy of clinical significance (MGCS) is rare and may present with scleredema‐like fibrosing skin disease.

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.

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.

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