Myositis as an Initial Presentation of Ulcerative Colitis before Gastrointestinal Symptoms.

The musculoskeletal system can be involved as an extra-intestinal manifestation of inflammatory bowel disease. Among these, myositis in ulcerative colitis (UC) is very rare. A 14-year-old girl was admitted due to severe shoulder tenderness. She had complained of left jaw pain and swelling for the past 10 days. Inflammatory markers were elevated with no evidence of infectious etiology. Myositis was suspected by shoulder magnetic resonance imaging. Three days after admission, she developed hematochezia. Muscle biopsy and colonoscopy was performed due to worsening left mandibular area pain and persistent hematochezia. Colonoscopy showed consistent findings with UC. She was finally diagnosed with UC with myositis as an extra-intestinal manifestation. She showed a dramatic response to UC treatment. Gastrointestinal symptoms were well-controlled. After 14 months, UC symptoms and muscle pain were aggravated, which were relieved after steroid and cyclosporin treatment. We report a unique case of UC initially presented with myositis, preceding gastrointestinal symptoms.