A new approach to wheezing in infants and preschoolers. Second of two parts: Toward a more effective treatment

Medical researchers are not certain about the specific type and timing of interventions to prevent such sequelae of asthma as airway remodeling and permanently reduced lung function. The Tucson Children's Respiratory Study performed pulmonary function testing on a cohort of infants followed through childhood. Results showed a loss of pulmonary function between 1 and 6 years of age in atopic or IgE-associated asthma.¹ According to Castro-Rodriguez and colleagues involved in the Tucson study, "it would be reasonable for clinicians treating infants and young children with recurrent wheezing to be more aggressive with those [patients] expected to be less likely to undergo remission from their symptoms" and develop a strategy for early intervention aimed at changing the natural course of the disease.² A number of studies provide evidence that using inhaled corticosteroids (ICS) not only results in good symptom reduction and control but may also preserve pulmonary function if used early in the course of the disease process, even in mild forms of asthma.^3-5

The National Asthma Education and Prevention Program (NAEPP) Expert Panel Report of 2002 based new recommendations for initiation of long-term control therapy for children 5 years of age and younger on the Tucson study's clinical index to define the risk of persistent asthma.^2,6

Many infants and young pre-schoolers with atopic wheezing may not meet the NAEPP 2002 recommendations for treatment because of genetic variation, environmental exposure history, overlap in asthma phenotypes, or delay in the presentation of atopic features. This might explain why a difference in severity of symptoms and response to treatment is often noted. For example: An infant or preschooler who is predisposed to IgE-associated or atopic asthma (but has not yet developed the NAEPP "risk factors for asthma") and has additional risk factors for transient early wheezing (reduced lung function at birth) and nonatopic wheezing (RSV lower respiratory tract infection and reduced regulation of airway tone) might experience more severe symptoms and have a less predictable prognosis for continued wheezing in childhood and altered lung function.

Collaborative managementA follow-up visit should be scheduled two to four weeks after initial diagnosis. This visit provides time to listen to the parents talk about what is working-and what is not. Follow-up visits are important for continued asthma education, goal setting, and ongoing development of a management plan. Improving outcomes with families involves using a written treatment plan and enforcing the information at every encounter, whether it is a well checkup or a visit for illness.⁸ Always take advantage of the teachable moment with family and child (Table 2).

When choosing medications and delivery devices, consider the family's ability to use them properly and consistently, and the child's development and temperament.⁷ Educating caregivers about proper medication delivery technique is very important in ensuring that the correct dosage is given (Table 3). The best, most expensive medication will be useless unless it is given correctly and for an adequate duration.

What's the prognosis?

Martinez and Godfrey offer the following advice for parents concerning their infant or young child's prognosis based on relative risk for nonatopic vs. atopic wheezing⁷:

Infants in this age group who have a personal or family history of atopy and have experienced onset of wheezing outside of the winter RSV season have a greater likelihood of developing atopic asthma that will persist into childhood and beyond.

Unfortunately, predictions of prognosis can be more difficult when the physician must consider the overlap of multiple risk factors, environmental exposures, and genetic variability.

No easy solutionPreventing new cases of asthma and episodic wheeze and developing strategies for successful treatment of existing cases should be a priority for clinicians and researchers. Perinatal and postnatal counseling of parents and caregivers on eliminating exposure of the fetus and young child to environmental tobacco smoke is the most significant way to decrease the incidence of new cases of recurrent wheeze and possibly atopy and persistent asthma.