TREATMENT OF RECURRENT VIRUS-INDUCED WHEEZING IN YOUNG CHILDREN

Viruses are widely recognized as common triggers of early childhood wheezing both in children with recurrent wheezing with multiple triggers as well as those with episodic exacerbations whose predominant trigger of wheezing is viral infections. In fact, a viral cause was detected in 90 percent of wheezing illnesses in a birth cohort of children at increased risk of developing asthma. Early childhood wheezing encompasses many clinical phenotypes, and responses to treatment are variable. Instituting or escalating asthma therapies is effective in controlling viral-induced wheezing symptoms in some patients. However, the evidence for this approach is not definitive in controlled studies, particularly in patients with intermittent symptoms.

The optimal management for acute episodes of virus-induced wheezing in infants and preschool children has yet to be determined. Therapeutic trials in this young population are hampered by the inability to predict clinical phenotypes, such as children who will outgrow their symptoms, children who will later develop asthma, and children who have bronchiolitis, a condition for which glucocorticoids generally are not recommended. This topic reviews the treatment of young children with recurrent virus-induced wheezing, defined as a minimum of three to four wheezing exacerbations a year. Virus-induced wheezing is a heterogeneous disorder, and response to treatment may differ among individuals. Inhaled short-acting beta₂-agonists are commonly used for symptomatic relief. Combination therapy with Hypertonic Saline (HS) and a bronchodilator is under investigation for treatment of acute symptoms. Inhaled and systemic glucocorticoids and Leukotriene-Receptor Antagonists (LTRAs) have been studied for the treatment and prevention of acute episodes of virus-induced wheezing in young children who require additional therapy.

 Inhaled bronchodilators are often first-line therapy for treatment of virus-induced wheezing and are an effective rescue treatment in symptomatic patients, especially in children with established asthma. However, inhaled short-acting bronchodilators have not been shown to improve clinical outcomes, decrease the rate of hospital admission, or decrease the duration of hospitalization in children with bronchiolitis. In addition, a systematic review and meta-analysis did not show benefit with the use of beta-agonists in children with acute cough or bronchitis, although the analysis was limited to two Pediatric trials.