What is the treatment for bronchiolitis obliterans, also known as popcorn lung?

Treatment for Bronchiolitis Obliterans (Popcorn Lung)

The treatment of bronchiolitis obliterans (popcorn lung) requires a multi-targeted approach including azithromycin therapy, immunosuppression management, and consideration of surgical interventions for refractory cases. 1

First-Line Medical Therapies

• Azithromycin therapy is recommended as a trial treatment for patients with bronchiolitis obliterans syndrome (BOS). The standard regimen is 250 mg daily for 5 days, followed by 250 mg three times weekly for a minimum of 3 months 1
• For patients currently on cyclosporine immunosuppression, switching to tacrolimus is recommended to mitigate lung function decline. Target therapeutic trough blood levels should range from 5-15 ng/mL for adult patients 1, 2
• Avoid long-term high-dose corticosteroids (>30 mg/day of prednisone) as they provide minimal benefit and increase risk of adverse effects 1

Management of Underlying Factors

• Aggressive treatment of any coexisting infections is essential, as infections can exacerbate BOS and worsen outcomes 1
• For patients with confirmed gastroesophageal reflux disease (GORD), surgical fundoplication should be considered to reduce the risk of further lung function deterioration 1
• Removal from exposure source is critical in cases of chemical-induced bronchiolitis obliterans (such as from diacetyl in microwave popcorn production) 3, 4

Advanced Therapies for Progressive Disease

• Extracorporeal photopheresis (ECPP) and total lymphoid irradiation (TLI) may be considered for selected patients with progressive BOS that is not responding to standard therapies 1
• For patients with end-stage BOS refractory to other therapies, lung re-transplantation should be considered as a last resort option 1

Monitoring and Follow-up

• Regular spirometry monitoring is essential to track disease progression and treatment response 1
• High-resolution CT imaging can help assess disease progression, though findings of air trapping and mosaic attenuation patterns lack sensitivity and specificity 1
• Bronchoscopy is frequently used to evaluate lung function decline, though it has poor sensitivity for diagnosing obliterative bronchiolitis 1

Special Considerations

• Mortality is significantly higher in patients with bronchiolitis obliterans, particularly in those with occupational exposure to diacetyl and related compounds 5
• The disease is irreversible, making early intervention critical to prevent further lung function decline 4
• Consumer exposure to butter-flavored microwave popcorn has been linked to cases of bronchiolitis obliterans, highlighting the importance of identifying and eliminating exposure sources 6

Treatment Algorithm

1. Initial approach: Start azithromycin trial therapy and optimize current immunosuppression
2. If on cyclosporine: Switch to tacrolimus
3. If GORD present: Consider surgical fundoplication
4. If progressive despite above: Consider ECPP or TLI
5. End-stage disease: Evaluate for lung re-transplantation

The prognosis for bronchiolitis obliterans remains poor, with increased COPD-associated mortality observed even years after exposure cessation, emphasizing the importance of early intervention and aggressive management 5.