Abstract
This paper reports on a 22-year-old male presenting with persistent chest pain accompanied by mediastinal emphysema. We firstly considered mediastinal emphysema induced by community-associated pnehumonia. Pathogen detection was performed but no positive results were found. Based on the results of a subsequent lung CT scan, PQ poisoning was suspected. Although there was no trace of PQ in the blood, the nebulizer masks used by patient at home was found to be positive for PQ. The diagnosis was ultimately established as PQ poisoning via inhalation with mediastinal emphysema. This case report explores the clinical manifestations, diagnostic challenges, and treatment complexities of inhaled PQ poisoning, emphasizing the importance of recognizing this rare poisoning route and its atypical symptoms.