Hypersensitivity pneumonitis secondary to Klebsiella oxytoca. A new cause of humidifier lung

Chest. 1993 Aug;104(2):627-9. doi: 10.1378/chest.104.2.627.


A 30-year-old woman developed recurrent episodes of fever, dyspnea, and nonproductive cough after repeated exposure to a home humidifier. The diagnosis of hypersensitivity pneumonitis was confirmed by detection of serum-binding antibodies at significant titer to Klebsiella oxytoca colonizing the humidifier water but not to other potential antigens. This represents a newly recognized cause of hypersensitivity pneumonitis related to exposure to K oxytoca contaminating a commercially available ultrasonic cold air home humidifier. The potential role for these frequently used home humidifier devices in unexplained pulmonary illness is emphasized.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Alveolitis, Extrinsic Allergic / diagnostic imaging
  • Alveolitis, Extrinsic Allergic / etiology*
  • Antigens, Bacterial / immunology
  • Equipment Contamination
  • Female
  • Humans
  • Humidity*
  • Klebsiella / immunology*
  • Lung / diagnostic imaging
  • Radiography
  • Water Microbiology


  • Antigens, Bacterial