Initial Treatment Approach for Diffuse Small Airway Disease

Diagnostic Assessment and Treatment Algorithm

The American Thoracic Society recommends complete pulmonary function testing to assess severity of small airway disease, high-resolution CT imaging with expiratory views to confirm presence of small airway disease, and ruling out other causes of symptoms including gastroesophageal reflux, postnasal drip, and asthma 1
Smoking cessation is strongly recommended for all patients with small airway disease 1
Inhaled bronchodilators and corticosteroids should be considered as initial treatment, with macrolide antibiotics as an option for persistent symptoms after excluding other causes, according to the American College of Chest Physicians 1, 2
For patients with physiological obstruction, inhaled short or long-acting bronchodilators should be started, and inhaled corticosteroids considered if inflammation is suspected 1
The American Thoracic Society suggests that a short course of systemic steroids (2-4 weeks) with repeat spirometry to determine reversibility may be beneficial for patients with suspected asthmatic component 1, 3
For persistent, nonreversible, symptomatic bronchiolitis, a short course (2-3 months) of empiric macrolide antibiotics (most commonly azithromycin 250 mg 3 days a week) may be considered 1

For patients with Sjögren's-associated small airway disease, humidification, secretagogues, and guaifenesin may be considered after excluding other causes, and anticholinergic medications should be avoided 1, 2
For patients with COPD-associated small airway disease, LABA/LAMA combinations are preferred over LABA/ICS for initial therapy due to better outcomes and lower risk of pneumonia, according to the American Thoracic Society 5
The American College of Chest Physicians recommends that long-term oral corticosteroid therapy should not be used due to side effect profile 5