Effectiveness of Inhaled Corticosteroids in Preschool Children Following Hospital Admission for Acute Dyspnea and Wheeze

Symptoms of dyspnea and wheeze occur frequently in young children with a cumulative incidence of 33% before the age of 3 and up to 50% by the age of 6 years. Most wheezing episodes in preschool children are associated with viral upper respiratory tract infections (episodic viral wheeze). The majority of children with episodic viral wheeze have become asymptomatic by the age of 6 years. About one in three preschool children with recurrent wheeze continue to wheeze after the age of six years, and these children are usually diagnosed with asthma.

Two clinical phenotypes of recurrent wheezing in preschool children can be distinguished. Children with episodic viral wheeze only wheeze with viral upper respiratory tract infections and are symptom free in between episodes. A minority of children wheeze during upper respiratory tract infection and with other trigger factors (such as smoke, fog, exercise) and this is defined as multiple trigger wheeze.

Inhaled corticosteroids (ICS) have been shown to be effective in preschool children with multiple trigger wheeze, but the effect is smaller than that in older children. This justifies a more critical approach towards such therapy, for example by prescribing a trial of ICS for a period of 3 months and evaluating the effect afterwards. Little research has been performed on the effect of ICS in preschool children with episodic viral wheeze. A high dose of ICS (>1600 ug/d) during an acute episode of dyspnea and wheezing has been shown to be effective, but in a number of small clinical trials maintenance treatment with ICS did not have an effect on the number and severity of episodes of viral wheezing. Contradictory results have been published about the effect of ICS in infants and preschool children with Respiratory Syncytial Virus bronchiolitis. Some studies showed a reduction of wheezing episodes after RSV bronchiolitis in children treated with ICS, two other studies did not show any positive effect.

Prescribing ICS in preschool children can result in adverse effects such as a reduced height growth. Because of the lack of evidence of effect of ICS in episodic viral wheeze, guidelines advise a critical approach towards prescribing ICS in episodic viral wheeze.