Inhaled corticosteroids (ICS) have been shown to reduce wheezing and asthma exacerbations in preschool-aged children (Pediatrics 2009 Mar;123(3):e519), and daily low-dose ICS treatment is recommended for children < 5 years old with persistent asthma (J Allergy Clin Immunol. 2007 Nov;120(5 Suppl):S94-138). However, daily ICS treatment has been associated with reduced growth in young children (N Engl J Med 2006 May 11;354(19):1985 ). The MIST trial evaluated the efficacy of intermittent ICS treatment for prevention of exacerbation in 278 children aged 12-53 months. Children with recurrent wheezing were randomized to inhaled budesonide 1 mg twice daily for 7 days only during respiratory tract illness (intermittent) vs. daily inhaled budesonide 0.5 mg. Inclusion criteria included at least 1 asthma exacerbation requiring systemic glucocorticoids, emergency care, or hospitalization in the previous year. Children were excluded for ≥ 6 courses of oral glucocorticoids or ≥ 2 hospitalizations for wheezing within 1 year.
A total of 213 children (76.6%) completed 1 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) (level 2 [mid-level] evidence). 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 1-year follow-up (N Engl J Med 2011 Nov 24;365(21):1990).
For more information, see the Asthma exacerbation in children and Corticosteroids for wheezing in children topics in DynaMed.