Should preschool wheezers ever be treated with inhaled corticosteroids?

The syndrome of preschool wheeze commonly regresses completely in the preschool years, but it may lead to prolonged symptoms and established asthma. Although epidemiological studies have established that there are several different phenotypes, it is currently impossible to assign the majority of wheezing preschool children to a phenotype prospectively. Bronchoalveolar lavage studies have shown an increase in total cellular inflammation in the youngest, symptomatic children, and that in older preschool children the neutrophil is the predominant inflammatory cell in the airway. Endobronchial biopsy studies have shown that eosinophilic inflammation and structural airway wall changes are absent in symptomatic infants but appear in severe wheezers by the age of 3 years. Treatment guidelines are not evidence based in this age group and frequently do not appear to consider either the likely pathology or the different patterns of symptoms. Pure virus-associated symptoms may be treated with intermittent beta-2 agonist or anticholinergics by inhalation. If this fails, intermittent oral leukotriene receptor antagonists or short courses of very high dose inhaled corticosteroids could be considered. The role of oral corticosteroids is highly debatable in young children with virus-associated wheeze. Prophylactic therapy may be considered for chronic intermittent symptoms (interval symptoms between acute episodes). The choices are oral leukotriene receptor antagonists, or inhaled corticosteroids, which should be introduced in a three-stage protocol to avoid overtreating the child with evanescent symptoms. Because the natural history of preschool wheeze is one of improvement, treatment should be tapered after a period of stability. Unfortunately, neither corticosteroids nor any other currently available therapy modifies the long-term outcome of preschool wheeze. In conclusion, corticosteroid treatment may have a small role in preschool wheeze, in particular for those thought to have early asthma, but the uncritical application of recommendations that are appropriate for older children and adults with asthma has led to widespread overuse of these medications. There is an urgent need for better treatment of preschool wheeze.