Level 2: Mid-level evidence
Inhaled corticosteroids (ICS) have been shown to reduce wheezing and asthma exacerbations in preschool-aged children (Pediatrics. 2009;123: e519-e525), and daily low-dose ICS treatment is recommended for children younger than age 5 years with persistent asthma ( J Allergy Clin Immunol. 2007;120:S94-S138). However, daily ICS treatment has been associated with reduced growth in young children (N Engl J Med. 2006;354:1985-1997).
The MIST trial evaluated the efficacy of intermittent ICS treatment for prevention of exacerbation in 278 children aged 12-53 months (N Engl J Med. 2011;365:1990-2001). Children with recurrent wheezing were randomized to inhaled budesonide 1 mg twice daily for seven days only during respiratory-tract illness (intermittent) vs. daily inhaled budesonide 0.5 mg.
Inclusion criteria included at least one asthma exacerbation requiring systemic glucocorticoids, emergency care, or hospitalization in the previous year. Children were excluded for six or more courses of oral glucocorticoids or two or more hospitalizations for wheezing within one year.
A total of 213 children (76.6%) completed one year of follow-up. There were no significant differences in the rates of exacerbation requiring oral glucocorticoids (0.95 vs. 0.97 per patient-year) or urgent-care visits for asthma (2.37 vs. 2.4 per patient-year).
Intermittent budesonide treatment was associated with a significant reduction in cumulative budesonide dose (mean 46 mg vs. 150 mg, P <0.05). There were no significant differences in time to first or second asthma exacerbation, or in change in height or weight from baseline at one-year follow-up.
Alan Ehrlich, MD, is a deputy editor for DynaMed, in Ipswich, Mass., and assistant clinical professor in Family Medicine, University of Massachusetts Medical School in Worcester.
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