Accumulating evidence indicates that there are at least two phenotypes of
wheezing in preschool years with distinct natural history. Frequent
wheezing in the first 3 years of life with risk factors for
asthma (e.g.,
eczema, maternal
asthma) predicts symptoms in older age, while infrequent viral-associated
wheezing without risk factors for
asthma has a benign prognosis. This systematic review summarizes evidence on the use of anti-inflammatory medications in preschool children with
wheezing. Literature search was performed using Medline and the Cochrane Library. Retrieved articles were critically appraised. Episodic use of high-dose inhaled
corticosteroids (>1,600 mcg/day of
beclomethasone) may ameliorate severity of intermittent viral-associated
wheezing. Maintenance inhaled
corticosteroids can control symptoms in children with frequent
wheezing associated with risk factors for
asthma. Inhaled
corticosteroids do not alter the natural history of
wheezing even when started early in life and could have a negative impact on linear growth rate. Short courses of oral
corticosteroids have been proposed as an effective measure to control exacerbations of symptoms although there is little evidence supporting their use. Some studies support the administration of non-steroidal anti-inflammatory medications (
leukotriene pathway modifiers, cromones, methylxanthines) for mild frequent
wheezing. Maintenance inhaled
corticosteroids is the most effective measure for controlling frequent
wheezing in preschool children, especially when accompanied by risk factors for
asthma. This treatment does not affect the natural history of
wheezing, although deceleration of linear growth rate is the most commonly recognized systemic adverse effect.