Successful early diagnosis and treatment in a case of Toxocara canis-induced eosinophilic myocarditis with eosinophil-rich pericardial effusion.

Fulminant myocarditis can become fatal if left untreated. Treatments for most types of myocarditis, including mechanical support, are limited. However, immediate systemic corticosteroids are known to be effective against eosinophilic myocarditis; therefore, prompt diagnosis of this disease is crucial. Unfortunately, the standard diagnostic tool for myocarditis, endomyocardial biopsy, does not provide immediate histopathological findings. Thus, a rapid diagnostic tool for identifying types of myocarditis is urgently required. We report here the first case of Toxocara canis-induced eosinophilic fulminant myocarditis which was diagnosed based on eosinophil-rich pericardial effusion where the patient recovered with early corticosteroid therapy.