Dermatomyositis (DM) is an inflammatory microangiopathy, affecting particularly the skin and muscles. The incidence ranges from 0.2 to 1.0/100 000; an overlap with other connective tissue diseases such as systemic sclerosis has been described, as has an association with cancer. Clinically DM is identified by a characteristic rash and a varying muscle weakness. The clinical diagnosis is confirmed by typical muscle histology.¹

A 60 year old man was admitted to our department with a 2 week history of muscle weakness, myalgias, dysphagia, a heliotrope rash on the eye lids, and bilateral acral finger ulcers. Creatine kinase (3879 U/ml, normal <171 U/ml) and C reactive protein (170 mg/l; normal <5 mg/l) were raised; autoantibodies (antinuclear antibodies (ANA), extractable nuclear antigen (ENA), anti-synthetase antibodies, rheumatoid factor, antineutrophil cytoplasmic antibodies (ANCA)) were negative. A muscle biopsy showed perivascular inflammation, an infiltrate predominantly of CD4+ T cells, and perifascicular atrophy, confirming the suspected diagnosis of DM. Despite the advanced age of the patient, the rapid onset of the manifestations, and the lack of autoantibodies, cancer associated myositis could be ruled …