Hypersensitivity Pneumonitis

Parenchymal lung disease (not the airway).  Causes irreversible restrictive disease (not COPD).

Provoked by specific environmental irritants:
  • Abrupt onset 4-8 hours after exposure
  • Cough, Dyspnea, ? Fever / Nausea
  • Resolves 12 hours after removal from irritant
Common among Farmers.  Maybe also among Bird Owners.
  • Long list of culprits: humidifiers, indoor pools, auto factories, saunas, printers’ & embalmers chemicals, mushrooms, etc. etc. etc.

Lung Sounds: Usually clear, sometimes rales, rarely wheezes.

  • CXR often normal
  • High-Resolution CT image of choice but may be normal
  • Irreversible damage may occur before seen on image

Send patients with suspect history & possible exposure to Pulmonary.

See posting Chronic Cough (end of post).