A case of refractory anti-MDA5-positive amyopathic dermatomyositis successfully treated with upadacitinib.

Amyopathic dermatomyositis (ADM) is a rare, idiopathic, connective tissue disease and melanoma differentiation-associated protein 5 (MDA5) antibody-positive ADM is more treatment-resistant, especially in patients with interstitial lung disease (ILD). The purpose of this article is to report a case of anti-MDA5-positive ADM successfully treated with JAK inhibitor Upadacitinib. A 35-year-old Chinese woman presented with recurrent itchy erythema on her face and scalp for 4 years. Upon examination, there were heliotrope erythema and eyelid edema, reddish rash on neck and scalp. Biopsy of the lesions was consistent with DM and a line blot assay confirmed the presence of anti-MDA5 antibodies. This patient was treated with oral Upadacitinib at a dosage of 30 mg daily. After 6 weeks of treatment, she achieved complete clinical remission with no reported side effects or instances of relapse. The antibody titer of anti-MDA5 was also decreased. Upadacitinib may be a potential drug candidate in patients with treatment-resistant ADM, especially in cases with refractory cutaneous conditions.