Sudden death in a toddler with laryngotracheitis caused by human parainfluenza virus-1.

Laryngotracheitis caused by human parainfluenza virus (HPIV) and not complicated by bacterial superinfection rarely causes sudden unexpected death in infants and toddlers, especially in the absence of stridor and a barking cough. We therefore describe a 15-month-old white male who died suddenly and unexpectedly with clinical and pathological features of laryngotracheitis caused by culture-proven HPIV-1 infection. Given the presence of mucosal inflammation extending into the vocalis muscle of the larynx without associated significant narrowing of the laryngotracheal airway lumen, we propose his death was a result of a laryngospasm, perhaps mediated by immune responses.