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Paediatric Pulmonology and Allergology
2007 April, Vol. X, No. 1 (3397-3422)
NEW EVIDENCE FOR THE ROLE OF INHALED STEROIDS IN THE TREATMENT OF PRE-SCHOOL WHEEZE
Andrew Bush
Imperial School of Medicine at National Heart and Lung Institute and Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, UK
The syndrome of pre-school 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 a number of different phenotypes, it is currently not possible accurately to assign the majority of wheezing pre-school 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 pre-school 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 three 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 β-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 debateable 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 over-treating the child with evanescent symptoms. Since 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 is modifies the long term outcome of pre-school wheeze. In conclusion, corticosteroid treatment may have a small role in pre-school wheeze, in particular those thought to have early asthma, but the uncritical application of recommendations that are appropriate for older children and adults with asthma has lead to widespread over-use of these medications. There is an urgent need for better treatment of pre-school wheeze.