Write a steroid prescription for hypersensitivity pneumonitis.

Steroid Prescription for Hypersensitivity Pneumonitis

For hypersensitivity pneumonitis, prescribe prednisone 0.5 mg/kg lean body weight daily for 4 weeks, then taper to 0.25 mg/kg/day for 8 weeks, with total treatment duration of at least 6 months before assessing response. 1

Initial Dosing Phase

• Start prednisone at 0.5 mg/kg lean body weight daily for 4 weeks as the initial high-dose phase to achieve disease control 1
• For patients with severe disease or respiratory failure, use prednisone 1-2 mg/kg/day 2
• Maximum daily dose should not exceed 60 mg 1

Taper Schedule

• After 4 weeks, reduce to 0.25 mg/kg/day for 8 weeks as the intermediate taper phase 1
• Total taper duration should be 4-8 weeks for severe cases 2
• Continue combined therapy for at least 6 months before making treatment decisions, as objective response may not be evident until after 3 months 1

Monitoring and Reassessment

• Assess response at 6 months using two or more of the following criteria on consecutive visits: decreased symptoms, reduced parenchymal abnormalities on HRCT, or physiologic improvement (>10% increase in TLC/VC, >15% increase in DLCO, or >4 percentage point increase in O2 saturation during exercise) 1
• If worse after 6 months: stop or change therapy 1
• If improved or stable after 6 months: continue combined therapy at same doses 1

Prophylaxis Requirements

• Add PCP prophylaxis (trimethoprim-sulfamethoxazole) if steroids ≥20 mg methylprednisolone equivalent for ≥4 weeks 2
• Start proton pump inhibitor for GI prophylaxis in all patients receiving steroids 2
• Initiate calcium and vitamin D supplementation with prolonged steroid use 2

Steroid-Sparing Strategy

• For patients unable to successfully taper off corticosteroids or experiencing unfavorable adverse effects, initiate mycophenolate mofetil (MMF) 500-1000 mg twice daily or azathioprine as steroid-sparing maintenance therapy 2, 1
• Consider adding these agents early rather than maintaining high-dose steroids long-term 1

Critical Caveats

• Avoid long-term high-dose corticosteroids (>30 mg/day prednisone) as they provide minimal benefit and increase adverse effects including cardiovascular disease, osteoporosis, infection, diabetes, and avascular necrosis 2, 1
• Antigen avoidance is paramount and must be implemented immediately - steroids alone without exposure cessation will not prevent disease progression 2, 3, 4
• For hot-tub lung specifically, complete avoidance of indoor hot-tub use is mandatory 2
• Corticosteroids have not been proven to slow worsening of fibrotic disease in prospective trials, so expectations should be managed accordingly 5