Diagnostic Code 6831 · 38 CFR §4.97
Hypersensitivity pneumonitis (HP) is an inflammatory lung disease caused by inhaling organic dusts, molds, chemicals, or other environmental antigens. Veterans may develop HP from exposure to moldy barracks, agricultural dusts, bird droppings in aircraft hangars, chemical agents, or industrial materials during service. Chronic HP can lead to permanent lung fibrosis.
| Rating | Criteria |
|---|---|
| 10% | Mild HP with minimal PFT impairment after antigen removal. Occasional symptoms with known exposures. |
| 30% | Chronic HP with moderate PFT impairment. Persistent symptoms despite antigen avoidance. Some fibrotic changes on imaging. |
| 60% | Advanced chronic HP with significant fibrosis and substantially reduced PFT values. Marked exercise limitation. |
| 100% | End-stage fibrotic HP causing respiratory failure or requiring continuous oxygen therapy. |
Documentation of antigen exposure during service (environmental reports, duty descriptions). High-resolution CT showing ground-glass opacities or fibrosis. PFTs including DLCO. Bronchoalveolar lavage or biopsy results if available. Pulmonologist diagnosis.
Common military sources include moldy living quarters, bird antigens in aircraft hangars or pigeon-contaminated buildings, agricultural dusts in rural deployments, chemical agents, and industrial materials in maintenance shops. Document your specific exposure in your claim.
Yes. Chronic HP can take months or years of repeated exposure to develop symptoms, and fibrotic changes may not be detected until well after the exposure ended. A nexus opinion explaining the delayed presentation can support your claim.