Pigeon Breeder's Lung: A case report of hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is an inflammatory disease caused by repeated inhalation of antigens. HP can mimic a variety of clinical processes from life-threatening anaphylaxis to insidious malignancy, and thus is often misdiagnosed. It is crucial for the clinician to correlate relevant exposure to onset of symptoms, and for the radiologist to provide appropriate differential diagnoses for prompt treatment. Radiological findings, when present, may include ground glass opacities and mosaic attenuation on CT. Clinical improvement upon removal of antigen helps cement diagnosis and facilitate the treatment of antigen avoidance and corticosteroids. We present an interesting case of hypersensitivity pneumonitis, particularly Pigeon Breeder’s lung, in a young man exposed to birds in a research laboratory whose symptoms occurred much sooner than the usual timeframe reported in the literature.