Hot tub lung

Hot tub lung refers to pulmonary disease in otherwise healthy patients that can occur by secondary exposure to aerosolized non-tuberculous mycobacteria in contaminated hot water-steam (classically described in hot tubs, hence the name). 

Clinical presentation

It can present as an acute pulmonary illness with fever and dyspnea.

Pathology

The pathology of hot tub lung is thought to be related to an infection, a hypersensitivity reaction (the latter is more favored) or both. Therefore it is also sometimes classified as a precipitant for hypersensitivity pneumonitis. A granulomatous pneumonitis then tends to occur.

Hypersensitivity pneumonitis-like reaction to mycobacteria can also occur from exposures other than just hot tubs.

Radiographic features

CT

Imaging appearances can mimic a subacute hypersensitivity pneumonitis from other causes ¹. Described features include ^1,5:

• areas of ground glass attenuation
• centrilobular pulmonary nodules
• air trapping on expiratory images
• beading of the interlobular septae

See also

• non tuberculous mycobacterial infection
  • pulmonary MAIC infection
• hypersensitivity pneumonitis