Pertussis Presenting as New-Onset Uncontrolled Asthma in Children: A Series of Three Cases.

Wheezing in children is most often attributed to asthma; however, infectious etiologies, such as Bordetella pertussis, may present with atypical manifestations, including wheezing, particularly in older children. Such presentations pose a diagnostic challenge and frequently result in misdiagnosis and delayed treatment. We describe three nonatopic school-aged children who presented with prolonged, predominantly nocturnal cough and wheezing and were initially managed as cases of new-onset uncontrolled asthma without clinical improvement. All were subsequently diagnosed with pertussis using multiplex polymerase chain reaction testing of throat swabs and demonstrated prompt clinical response to azithromycin therapy. These cases highlight pertussis as an important asthma mimic in older children and underscore the need for heightened clinical suspicion in patients with persistent cough, poor response to bronchodilators and inhaled corticosteroids, normal inflammatory markers, and relative lymphocytosis. Early recognition is critical to reduce morbidity and limit ongoing transmission, particularly in tropical and resource-limited settings where pertussis may be underdiagnosed.