A randomised, double-blind study funded by the US National Heart, Lung, and Blood Institute examined the effect of a temporary 5-fold increase in inhaled steroids in 254 children aged 5 to 11 years with mild to moderate persistent asthma who had at least one asthma exacerbation treated with systemic steroids in the previous year.
The children were treated for 48 weeks with a maintenance low-dose inhaled steroid and were randomised to continue with the same dose or use a quintupled dose for 7 days at the early signs of exacerbation (the ‘yellow zone’). The primary endpoint was the rate of severe exacerbations leading to treatment with systemic steroids.
Analysis showed that the rate of severe exacerbations was not significantly different between the two treatment groups, with 0.48 exacerbations per year in the high-dose group and 0.37 exacerbations per year in the low-dose group (relative rate 1.3 [95% CI 0.8–2.1], p=0.30).
Additionally, there was no improvement in other asthma outcomes, including time to first exacerbation, symptom scores or salbutamol use while in the 'yellow zone'.
Reduced growth rate
The researchers also found that temporarily increasing the dose of inhaled steroids reduced the linear growth rate. Children in the high-dose group grew 0.23cm per year less than children in the low-dose group (p=0.06).
The authors of the study concluded that increasing the dose of inhaled steroids at early signs of an exacerbation was no more effective at preventing progression to a more severe exacerbation or improving other asthma outcomes, and may be linked with diminished growth rate.
'Our study suggests we need to find better ways to identify early signs of asthma worsening that are likely to lead to more serious asthma exacerbations,' said study author, Dr Kristie Ross.
'Parents should continue to work with their child's asthma doctor to develop a personalised home management plan that includes 'yellow zone' interventions,' she added.