Colonic vasculopathy and perforation in the initial presentation of adult dermatomyositis in a patient with improving muscle weakness.

A 63-year-old woman with diabetes presented with 8 weeks of proximal muscle weakness and change in bowel habits. Muscle biopsy confirmed myositis, and serological studies were consistent with dermatomyositis (DM), without evidence of overlapping connective tissue disease or malignancy. On day 12 of prednisone therapy and after receiving one dose of IVIG with improvement in muscle strength, the patient developed abdominal pain and was diagnosed with a gastrointestinal (GI) perforation and peritonitis requiring emergent colectomy. The pathology revealed diffuse mucosal ulceration, prominent lymphoplasmacytic infiltration, venous occlusion and arterial hyperplasia. Although GI manifestations due to GI vasculopathy are rare in adult DM and are often a delayed complication, in this patient, it was one of the initial manifestations of this condition. In addition to being a fatal complication, clinicians should be aware of these complications, as immunosuppression used to control the muscular and cutaneous inflammation may not control the GI vasculopathy.