Pertussis-Associated Myocarditis in an Adolescent: A Case Report.

Myocarditis is an uncommon complication of infectious diseases in children, most often viral in origin. Bordetella (B.) pertussis infection rarely causes myocardial involvement, with very few cases reported in the literature and even fewer in adolescents. We describe a rare case of acute myocarditis in a previously healthy 16-year-old male with confirmed B. pertussis infection, who presented atypically with abdominal pain and rash in the absence of a characteristic pertussive cough. Review of prior reports suggests pertussis myocarditis in adolescents is exceptionally rare, with variable presentations but generally favorable outcomes. While myocarditis has also been reported extremely rarely following pertussis-containing vaccines, no causal relationship has been established. This case highlights the importance of considering pertussis in the differential diagnosis of myocarditis, even when respiratory features are absent.