Abstract
Overlap myositis refers to the simultaneous occurrence of myositis and another systemic autoimmune disease. Association between psoriasis and inflammatory myopathy is uncommon. Tumor necrosis factor (TNF)‐alpha antagonists are used to treat patients with psoriasis and arthritis associated with psoriasis. Although the use of TNF‐alpha–blocking agents increases the risk of developing myopathy more than 4 times in people with psoriasis, this association is underrecognized. Here, we describe the case of a young male who developed inflammatory myopathy after the use of TNF‐alpha blocking therapy for the treatment of psoriasis, associated with cN‐1A and NXP2 autoantibodies. After cessation of the TNF‐alpha blocking agent and pulse corticosteroid therapy, the patient showed a good response, with increased muscle strength and decreased creatine kinase levels. This case highlights the importance of monitoring for muscle symptoms in patients treated with anti–TNF‐alpha agents and the heterogeneous clinical phenotypes that can occur with each autoantibody.