Diagnosis of Concomitant Myocarditis in a 13-Year-Old Patient with Crohn's Disease.

Extraintestinal manifestations (EIMs) of inflammatory bowel disease (IBD) are diverse; however, cardiac manifestations are rare. Herein, we report a case of myocarditis associated with Crohn's disease (CD) in a 13-year-old boy. The patient was hospitalized for an evaluation of IBD due to recurrent abdominal pain and diarrhea for several months. On the second day of hospitalization, the patient complained of shortness of breath and chest discomfort. Chest radiography revealed cardiomegaly and pulmonary edema with sinus tachycardia on electrocardiogram (ECG). Echocardiography revealed slight right ventricular (RV) dysfunction and mild left ventricular (LV) dilatation. Laboratory results revealed elevated levels of cardiac markers and soluble suppression of tumorigenicity (sST2), both of which indicated fulminant myocarditis. The patient was diagnosed with acute myocarditis and treated in the intensive care unit, where he had massive and intermittent episodes of bloody stools. Several studies for the diagnosis of IBD were continued after the patient improved. Additional capsule endoscopy revealed multiple ulcers with active bleeding in the small intestine. Therefore, CD with small intestine involvement was diagnosed. This is the first reported case of myocarditis co-occurring as an EIM in pediatric CD. The occurrence of myocarditis in IBD and gastrointestinal bleeding are considered to be related to vasculitis.