Acute Lung Injury Caused by Mugwort Steaming.

Mugwort steaming is a traditional health practice with reported biological benefits, but its potential adverse effects on lung health remain unexplored. We report a case of a 48-year-old Japanese female who developed recurrent respiratory symptoms and abnormal lung shadows following occupational exposure to mugwort steaming. Initial diagnosis suggested nonfibrotic hypersensitivity pneumonitis. However, transbronchial lung cryobiopsy revealed findings consistent with acute lung injury (ALI). Multi-disciplinary discussion led to a final diagnosis of ALI caused by mugwort steaming. The patient's condition improved when mugwort steaming was discontinued. This case represents the first reported instance of ALI associated with mugwort steaming. It highlights the need for caution in traditional practices and emphasizes the importance of considering unconventional exposures in unexplained lung pathologies. Further research is warranted to establish the safety profile and potential risks of mugwort steaming.