Supplementary Material for: Successful Treatment of Refractory Dermatomyositis with Deucravacitinib (Sotyktu): A Case Report.

Introduction: Clinically amyopathic dermatomyositis (CADM) is a subtype of dermatomyositis (DM) characterized by cutaneous findings without clinically apparent muscle involvement. While immunosuppressive therapies such as methotrexate, mycophenolate mofetil, and hydroxychloroquine are commonly used, treatment-resistant cases remain a challenge. We present a case of refractory CADM successfully treated with Deucravacitinib, a selective TYK2 inhibitor. Case Presentation: A 50-year-old woman with a three-year history of CADM presented with persistent facial erythema, heliotrope rash, violaceous erythema on sun-exposed areas, and Gottron’s sign. Despite multiple systemic treatments, including methotrexate, mycophenolate mofetil, hydroxychloroquine, and topical and oral roflumilast, she continued to experience skin involvement and associated pain. Deucravacitinib 6 mg daily was initiated, leading to near-complete resolution of cutaneous lesions and complete resolution of pain within ten weeks. At six months, her response remained stable, and she continues treatment with ongoing monitoring. Conclusion: This case highlights Deucravacitinib as a potential treatment option for refractory CADM. By selectively inhibiting TYK2, it targets key inflammatory pathways involved in DM pathogenesis while minimizing off-target effects. Further studies are needed to evaluate its long-term safety and efficacy in this patient population.