Hypersensitivity pneumonitis due to unclean continuous positive airway pressure equipment.

Hypersensitivity pneumonitis is a potentially fatal immunological lung disease caused by occupational or environmental exposure to specific antigens. Here, we report on an obstructive sleep apnea patient whose hypersensitivity pneumonitis was aggravated because of the use of unclean continuous positive airway pressure equipment. This report shows that careful history taking is important when diagnosing hypersensitivity pneumonitis. Sleep specialists should be aware of the risks related to unclean continuous positive airway pressure equipment use, and obstructive sleep apnea patients should be instructed and monitored in the regular cleaning of their equipment.