Abstract: We report a case of a 16-year-old boy who was treated for a suspected dental infection with a tooth extraction and amoxicillin therapy. The decedent developed a rash and presented to the emergency department with what was thought to be a possible allergic reaction to amoxicillin despite completion of the antibiotic course. The patient was given a course of prednisone. Several weeks later, while still completing the course of prednisone, the patient experienced shortness of breath and collapsed. Resuscitation efforts were unsuccessful. Postmortem examination revealed a necrotizing eosinophilic myocarditis. This case reveals that despite steroid therapy, a patient may still die of eosinophilic myocarditis.