Farmers' lung

Farmers' lung is a hypersensitivity pneumonitis, an inflammatory lung disease caused by repeated inhalation of organic dusts, typically from moldy hay or other agricultural products. It is an immune-mediated reaction leading to inflammation of the alveoli and small airways.

This code is used for documented cases of extrinsic allergic alveolitis specifically attributed to exposure to agricultural dusts. Documentation should clearly indicate a history of exposure in an agricultural setting and clinical findings consistent with hypersensitivity pneumonitis.

• Differentiate from other forms of hypersensitivity pneumonitis by confirming the specific agricultural exposure.
• Ensure documentation specifies "Farmers' lung" or clearly links the pneumonitis to moldy hay or similar agricultural dusts.
• Consider sequencing with codes for acute or chronic manifestations if specified in the documentation.