A hidden danger: lung abscess following inhalation of kerosene-based pyrethroid insecticide spray.

Abstract

Background: Pyrethroid insecticides are widely used because of their low toxicity in humans. Spray-type pyrethroids are often formulated with kerosene as a carrier solvent, and inhalation of kerosene-containing products can lead to pneumonitis and the formation of lung abscesses. We report a case of chemical pneumonitis resulting in the development of a lung abscess due to the intentional inhalation of pyrethroids.

Case presentation: A man in his 50s in a psychiatric hospital for transient psychotic disorder attempted suicide during an overnight leave from the hospital. He drank sodium hypochlorite, put a nylon bag over his head, and sprayed pyrethroid insecticide inside the bag. He was found collapsed and was transported to our emergency room. On arrival, his SpO₂ was 100% on O₂ at 10 L/min by mask (100% on room air at ambulance arrival), his circulation was stable, and his Glasgow Coma Scale score was 10 (E1V3M6), which improved to 15 (E4V5M6) in about one hour. A chest computed tomography (CT) scan showed ground-glass shading in both lungs. We diagnosed him as having pneumonia and started antimicrobial therapy. On day 13 of hospitalization, we found multifocal hypo-absorptive areas, and a diagnosis of lung abscess was made based on CT imaging, and antimicrobial therapy was continued. During the hospitalization, he expectorated bloody sputum. A contrast chest CT scan obtained on day 71 of hospitalization showed a pseudoaneurysm in the abscess cavity, for which we performed successful transcatheter coil embolization. On day 77, the abscess was shrinking, and he was transferred to another hospital for continued treatment. However, he again had bloody sputum and was transferred back to our hospital on day 113. Another contrast chest CT scan revealed the formation of a new aneurysm, and on day 114, we successfully performed coil embolization again, and he was transferred back to the other hospital on day 116.

Conclusion: Spray-type pyrethroid insecticides contain the organic solvent kerosene. Inhalation of kerosene has been reported in several cases of chemical pneumonitis leading to lung abscess. Clinicians should pay attention to kerosene contained in insecticides and the circumstances under which they are used. Early recognition and aggressive treatment can likely prevent severe outcomes.