Bird-fanciers' lung

This code represents an extrinsic allergic alveolitis, specifically hypersensitivity pneumonitis, caused by exposure to avian antigens. It is an inflammatory lung disease resulting from an immune response to inhaled proteins found in bird droppings, feathers, or dander.

Apply this code when documentation clearly indicates a diagnosis of bird-fanciers' lung, often presenting with symptoms like dyspnea, cough, and fever following exposure to birds. Supporting documentation should include a history of bird exposure and diagnostic findings consistent with hypersensitivity pneumonitis.

• Differentiate from other forms of hypersensitivity pneumonitis by ensuring the specific avian antigen exposure is documented.
• Do not use for general allergic reactions or asthma without specific lung involvement due to bird antigens.
• Consider sequencing this code as a primary diagnosis when it is the reason for the encounter, or as a secondary diagnosis if it is a co-morbidity affecting treatment.