Chemical epiglottitis causing airway compromise after benzalkonium chloride ingestion.

Benzalkonium chloride, a quaternary ammonium compound with disinfectant properties, produces caustic effects at concentrations of 0.1% or higher. However, the relationship between the characteristics of the ingested substance and clinical severity, including airway compromise, is not always straightforward. A 77-year-old man presented with odynophagia and drooling after accidentally ingesting only 1 mL of 10% benzalkonium chloride and 1% isopropyl methyl phenol (Neotraban Green®). Given the risk of airway compromise, emergency endotracheal intubation was performed. Despite the high concentration, no oral, esophageal, or gastric injury was observed. Flexible laryngoscopy revealed marked epiglottic and arytenoid swelling, leading to a diagnosis of chemical epiglottitis. Even minimal ingestion of high-concentration benzalkonium chloride can cause life-threatening upper airway injury. Clinicians should maintain a high index of suspicion for airway compromise in cases of caustic ingestion based not only on ingested volume but also on clinical signs.