Role of Systemic Corticosteroids in Acute Exacerbation of Hypersensitivity Pneumonitis

Therapeutic Approach to Acute HP Exacerbations

Systemic corticosteroids should be administered promptly in acute exacerbations of HP to reduce inflammation and prevent further lung damage, as recommended by the American Thoracic Society 1
For acute non-fibrotic HP exacerbations, prednisone starting at 40 mg daily for several weeks has been studied in controlled trials, with evidence suggesting its efficacy in improving lung function 1
Oral administration is preferred when possible, as it is less invasive while maintaining efficacy similar to intravenous routes, according to the American Academy of Allergy, Asthma, and Immunology 2

Improvement in diffusion capacity (DLCO) has been documented after 1 month of treatment in controlled studies, with a significant increase in lung function measures observed in pediatric patients with non-fibrotic HP 1
Corticosteroids can reverse the monthly decline in forced vital capacity (FVC) in non-fibrotic HP, with a study showing a reversal from -0.35% to +0.84% per month 1
Resolution of radiographic abnormalities has been documented in up to 80% of treated patients, highlighting the effectiveness of corticosteroids in acute HP exacerbations 1

Corticosteroids are most effective in acute and subacute forms of HP without established fibrosis, with evidence suggesting their ability to improve lung function and prevent disease progression 1
In patients with established fibrosis, corticosteroids alone may not significantly change FVC or DLCO, highlighting the need for alternative treatment strategies 1

Short-term use of systemic corticosteroids may cause hyperglycemia, weight gain, and insomnia, with evidence suggesting a significant risk of adverse effects 3, 4
Long-term use carries risks of infection, osteoporosis, and adrenal suppression, emphasizing the need for careful monitoring and management 3, 4