Management of hypersensitivity pneumonitis

Comprehensive antigen remediation, if identified

Monitor, no treatment required
Lifetime Ag avoidance

Consider oral steroids (e.g., prednisone 0.5–1 mg/kg/day × 4–6 wk, with taper for total 3 mo)
Clinical reassessment at 3 mo
Lifetime Ag avoidance

End

Consider oral steroids (e.g., prednisone 0.5–1 mg/kg/day × 4–6 wk, with taper for total 3 mo)
Consider initiating steroid-sparing drug (e.g., MMF or AZA)
Clinical reassessment at 3 mo
Lifetime Ag avoidance

Monitor
Consider steroid-sparing drugs if prolonged corticosteroid treatment is required (e.g., severe/extensive disease) or intolerable steroid side effects

Clinical stability after steroid taper?

Yes

No

Duration of treatment unclear
Guided by disease behavior

Consider antifibrotic therapy
Refer to lung transplant program, if appropriate
Supportive therapy, including oxygen and pulmonary rehabilitation
Consider advanced immunosuppressive therapy
Enroll in clinical trial

Clinical stability?

Yes

No

Predominantly inflammatory disease (GGO on HRCT, no fibrosis), mild and stable clinical presentation

Predominantly inflammatory disease (GGO on HRCT, BAL lymphocytosis), severe clinical presentation (hypoxemia)

Predominantly fibrotic disease (fibrosis on HRCT, no BAL lymphocytosis), severe clinical presentation (hypoxemia)