Summary

A 70-year-old female with a 10-year history of dermatomyositis involving the skin, muscles, and gastrointestinal system was diagnosed based on proximal muscle weakness, typical dermatomyositis-specific rashes, elevated creatine kinase, and muscle biopsy findings consistent with dermatomyositis. Myositis-specific autoantibodies were negative.

The patient initially received treatment with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) but experienced gastrointestinal intolerance to both methotrexate and azathioprine. Subsequently, she was managed with intravenous immunoglobulin (IVIg) for 4 years; however, due to a relapse of muscle involvement, rituximab was initiated and has been administered for the past 3 years.

Over the last year, the patient achieved remission in muscle involvement but experienced worsening dermatomyositis-specific skin manifestations, including heliotrope rash, Gottron signs, and holster sign [Figure 1A], accompanied by severe pruritus that significantly impaired her quality of life. The Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) activity score reached 17. Her skin condition remained refractory despite treatment with topical steroids and calcineurin inhibitors.