Things We Do for No Reason: Systemic Corticosteroids for Wheezing in Preschool-Aged Children

The Asthma Predictive Index (API), a tool developed as a part of the Tucson Children’s Respiratory Study, uses clinical factors including history of wheeze, atopic dermatitis, and allergic rhinitis to determine a young child’s risk of having asthma symptoms after age six years.²¹ Jartti et al. and Panickar et al. used the API to stratify patients based on future asthma risk.^13,15 The high risk group in the Jartti et al. study showed the benefit of SCS, while there was no benefit in the Panickar et al. study. When Oommen et al. also attempted to stratify asthma risk using levels of blood eosinophil proteins, which when elevated, are predictive of persistent wheeze.¹⁴ There was no difference in drug efficacy between patients with high and low blood eosinophil proteins. Although Foster et al. demonstrated shorter length of stay (LOS) with SCS overall, this was only seen in the subgroup with a previous diagnosis of asthma.

Patients presenting with severe disease (including those requiring critical care or with the highest symptom scores) have mostly been excluded from these studies. Although patients with severe disease often receive steroids, there is insufficient evidence of the efficacy of SCS in this population.^12,13,15,22 Foster et al. did include patients with high symptom scores (although they excluded patients with “critical wheeze”) and found that the efficacy of SCS was clearest for those with severe presentations.¹¹

Finally, some studies have demonstrated a virus-specific effect, with a reduction in time to readiness for discharge and reduction in recurrent wheeze in children treated with prednisolone who were positive for rhinovirus.^12,23 Rhinovirus infection has also been associated with allergic sensitization and recurrent wheezing.^23,24 However, rhinovirus-specific steroid responsiveness has not been consistently replicated by other investigators.¹¹

The majority of preschool-aged children presenting with wheeze in the care of hospitalists have mild to moderate symptoms, triggered by viral infections.²² It can be helpful to categorize the wheezing child as atopic or nonatopic. Laboratory studies such as allergen-specific IgE, peripheral eosinophil count, and exhaled nitric oxide can aid in predicting response to asthma medications and progression to the classic asthma phenotype.²⁵ In the absence of these diagnostic studies, which are often costly and challenging to obtain in young children, a clinical score such as the API, or the recently validated Pediatric Asthma Risk Score (PARS), can help to assess future risk of developing multitrigger asthma.^21,26 A positive API requires a history of more than three episodes of wheeze over the past year as well as one major (physician-diagnosed atopic dermatitis or parental asthma) or two minor (peripheral blood eosinophilia, physician-diagnosed allergic rhinitis, or wheezing apart from colds) criteria.¹⁷ It has a sensitivity of 57% and specificity of 81%.²⁶ The PARS uses the presence of parental asthma, eczema, early wheezing, wheezing apart from colds, African-American race, and ≥2 positive skin prick tests to predict asthma. The sensitivity and specificity of PARS are similar to the API at 68% and 79%, respectively.²⁶

Given the mixed results from studies evaluating the benefit of SCS in preschoolers with atopic symptoms and/or a positive API, evidence is lacking to guide decision-making in these children.^13-15 However, it is reasonable to treat those at higher risk for future multitrigger asthma with SCS. There is also insufficient evidence to determine whether those with more severe disease or those infected with particular viral pathogens may benefit. Therefore, for the majority of children presenting with viral-induced wheezing, with a negative API or low PARS, there is no evidence that treatment with an SCS provides benefit in the form of reduced LOS, reduction in clinical symptoms, treatment failure, or relapse rate.