Effects of inhaled versus systemic corticosteroids on exhaled nitric oxide in severe acute asthma

Summary Background There is a paucity of information on the differential effects of systemic versus inhaled corticosteroids on airway inflammation in patients with acute asthma. This study aimed to evaluate the effects of stopping systemic corticosteroids while maintaining the inhaled corticosteroids (ICS) on airway inflammation, lung function and asthma symptoms in patients who had been discharged from hospital after treatment for severe acute asthma. Methods Twenty-four adult patients with severe exacerbations of asthma were treated with both oral and inhaled corticosteroids after discharge from hospital. Oral corticosteroids were stopped after 1 week. Spirometry, asthma quality of life questionnaire (AQLQ) score and exhaled nitric oxide (NO) were measured at discharge, 1 week, and 2 weeks after discharge. Results Withdrawal of oral corticosteroids resulted in significant rebound in mean exhaled NO by 11.0 ppb (95% CI, 4.9–17.1 ppb, p < 0.001) or 47.7% (95% CI, 22.4–73.1%) despite uninterrupted ICS treatment. The rebound in exhaled NO occurred despite significant improvement in the mean AQLQ score ( p = 0.006) and frequency of reliever use ( p = 0.003) and was not associated with significant change in the mean FEV1 ( p = 0.64). Conclusions In patients discharged from hospital after treatment for asthma exacerbations, withdrawal of oral corticosteroids resulted in increase in exhaled NO levels despite continued ICS treatment.