Abstract: Pretibial myxedema (PTM) is an autoimmune dermatosis associated with Graves' disease, characterized by mucopolysaccharide deposition in the dermis and edematous plaques on the anterior tibia. Clinical treatment options are limited with suboptimal efficacy. Recently, there have been reports that tofacitinib can significantly improve PTM lesions. This paper reports a case of hypothyroidism complicated with PTM treated with upadacitinib. The patient was a 55-year-old female with a 3-year history of hypothyroidism. Two months prior to admission, she presented with symmetric swelling of both lower legs and feet without definite cause, accompanied by local peau d'orange skin changes and persistent pruritus, and the symptoms gradually aggravated. She was diagnosed with PTM and treated with oral upadacitinib combined with levothyroxine for thyroid function adjustment. After 7 months of treatment, the patient's edema completely resolved, epidermal pruritus and peau d'orange lesions improved significantly, and no adverse reactions occurred.

Key words: pretibial myxedema, upadacitinib, JAK1, Graves' disease