Imaging of Hypersensitivity Pneumonitis.

The management of hypersensitivity pneumonitis (HP) depends on early identification of the disease process, which is complicated by its nonspecific clinical presentation in addition to variable and diverse laboratory and radiologic findings. HP is the result of exposure and sensitization to myriad aerosolized antigens. HP develops in the minority of antigenic exposures, and conversely has been documented in patients with no identifiable exposure, complicating the diagnostic algorithm significantly. Prompt diagnosis and early intervention are critical in slowing the progression of irreversible parenchymal damage, and additionally in preserving the quality of life of affected patients.