Controversies in the Treatment of the Acutely Wheezing Infant

Abstract

Frequently, the first wheezing episodes in young children are associated with viral infections. Preschool children with wheezing experience disproportionately high morbidity and health care utilization, including a 50% greater rate of ambulatory visits, nearly double the rate of emergency department (ED) visits, and nearly triple the rate of hospitalization relative to school-age children (1). Furthermore, particular viruses have been proposed to lead to the establishment of the asthmatic phenotype (2, 3). Children who experience severe viral respiratory infections in early life have a higher chance of developing asthma later in childhood (2, 4, 5). It has also been postulated that the immune system of susceptible infants may have delayed maturation leading to allergic sensitization and may not be able to mount an adequate antiviral defense, increasing the likelihood of virus spreading to the lower airways resulting in a severe low respiratory tract infection (6). Furthermore, the presence of both early-onset allergic sensitization and wheezing respiratory illnesses confer the highest risk of developing persistent asthma (7), suggesting that both of these processes may injure the airway, leading to inflammation, hyperresponsiveness, and recurrent wheezing. The management of these wheezing episodes remains a distinct clinical challenge in 2011. While research over the last two decades has shed substantial light on this problem, clinicians remain uncertain as to the optimal management strategies in this heterogeneous population.