Acute peri-myocarditis with an unusual initial manifestation of gallbladder edema and a profound eosinophilic surge during convalescence.

A 29-year-old man with fever and right upper quadrant pain was referred to our hospital. Ultrasonography revealed intense gallbladder edema and pericardial effusion. Despite no symptoms and signs related to heart failure, the patient was clinically suspected of cardiac dysfunction related to acute peri-myocarditis based on his symptoms of preceding fever and headache, pericardial effusion, positive troponin T value, elevated B-type natriuretic peptide level, and sequential changes on electrocardiography. With a profound eosinophilic surge (8,022/µL) during convalescence, acute peri-myocarditis and gallbladder edema resolved spontaneously. This case instructively shows that acute peri-myocarditis initially manifests with abdominal symptoms, mimicking acute acalculous cholecystitis. In addition, an extensive review of acute myocarditis cases with peripheral eosinophilia suggests that there is a subgroup characterized by a predilection for young and middle-aged men, concurrence of pericardial effusion, transient eosinophilic surge during convalescence, and favorable outcome.