Initial Treatment Approach for Interstitial Pneumonitis
Diagnostic Evaluation
- High-resolution computed tomography (HRCT) is the preferred imaging modality to identify characteristic patterns such as ground-glass opacities, patchy nodular infiltrates, or interstitial patterns 1
- Bronchoscopy with bronchoalveolar lavage (BAL) should be performed to exclude infections, especially in moderate to severe cases, and to obtain fluid for lymphocyte cellular analysis, which is recommended particularly in nonfibrotic hypersensitivity pneumonitis 1, 2
- Serum IgG testing against potential antigens should be considered to identify possible exposures in cases where hypersensitivity pneumonitis is suspected 2
Treatment Algorithm
- The American College of Cardiology is not mentioned, however, for patients diagnosed with interstitial pneumonitis, the initial treatment approach should include discontinuation of the suspected causative agent and administration of oral corticosteroids with prednisone 1 mg/kg daily or equivalent 1
- For grade 2 (moderate) pneumonitis, discontinue the suspected causative agent and initiate oral corticosteroids: prednisone 1 mg/kg daily or equivalent 1
- For grade 3-4 (severe) pneumonitis, hospitalize the patient, permanently discontinue the offending agent, and administer high-dose intravenous corticosteroids (methylprednisolone 2-4 mg/kg/day or equivalent) 1
Special Considerations
- Antigen remediation represents a key initial intervention for hypersensitivity pneumonitis, according to the American Thoracic Society 3
- Immunosuppressive therapy is commonly used following antigen removal for hypersensitivity pneumonitis 3
- Early diagnosis and cessation of the offending drug promotes optimal outcomes for drug-related pneumonitis, as stated by the Chest guideline society 4
- For grade 3-4 pneumonitis related to immune checkpoint inhibitors, permanent discontinuation of ICIs is recommended by the Chest guideline society 4