Long-term studies of the natural history of asthma in childhood

It's time to rethink mite allergen avoidance

The role of allergen exposure in the etiology of allergic sensitization and asthma is complex. Advice on strategies to avoid domestic allergens remains contentious because trials of interventions aimed to prevent asthma or reduce symptoms have often failed to demonstrate benefits. Asthma management guidelines differ widely in their recommendations, while Web-based information often claims benefits associated with products. In this rostrum we argue that although many factors have a role in both the etiology and the exacerbation of asthma, allergen exposure probably remains an important contributor to the manifestations of the disease. Currently, there is no evidence-based framework for effective domestic allergen avoidance interventions to reduce chronic aeroallergen exposure. The development of an effective approach to allergen avoidance requires a better understanding of (a) the physical nature of chronic aeroallergen exposure and methods for measuring and reducing this, (b) the interaction between allergen exposure and innate immune modulators at different disease stages, and (c) markers enabling the identification of individuals who would benefit from this. The strategic risk of overemphasizing other novel mechanisms and approaches to asthma management is that we will prematurely abandon and fail to improve an existing approach that could have a significant impact on the development, progression, and symptoms of the disease.

New insights into asthma pathogenesis and treatment

Although national asthma guidelines help organize standards for asthma care, current asthma management is still primarily symptom based. Recent reports provide insights on how to improve asthma management through steps to better understand the natural history of asthma, individualize asthma care, reduce asthma exacerbations, manage inner city asthma, and some potential new ways to use available medications to improve asthma control. Despite many significant gains in managing asthma, we must now find improved strategies to prevent asthma exacerbations, alter the natural history of the disease, and to reduce health disparities in asthma care. Perhaps new directions in personalized medicine including a systems biology approach, along with improved health care access and communication will lead to better methods to alleviate the burden of asthma. This review will discuss the benefits and limitations of the current approach to asthma management, new studies that could impact new directions in asthma management, and new insights related to mechanisms of asthma and allergic airways inflammation that could eventually lead to improved asthma control.

Predicting the long-term course of asthma in wheezing infants is still a challenge

Background. In recurrent wheezing infants, it is important to identify those likely to remain asthmatic in order to propose appropriate long-term management. Objective. To establish predictive factors for persistent asthma at adolescence in a population of recurrent wheezing infants. Methods. Retrospective study of 227 infants. Inclusion criteria were age under 36 months, a history of at least three wheezing episodes assessed via a doctor-led ISAAC questionnaire and a standardized allergy testing programme. At 13 years, active asthma was assessed by questionnaire. Results. Risk factors for asthma persisting into adolescence were allergic sensitization to multiple airborne allergens (OR 4.6, CI-95% (1.9–11.2) P = 0.001), initial atopic dermatitis (OR 3.4, CI-95% (1.9–6.3) P < 0.001), severe recurrent wheezing (OR 2.3, CI-95% (1.3–4.2) P = 0.007), and hypereosinophilia ≥470/mm³ (OR 2.2, CI-95% (1.07–4.7) P = 0.033). Conclusion. While it is still difficult to predict the long-term course of asthma, atopy remains the major risk factor for persistent asthma.

Inhaled Corticosteroids Should Be Used in Infants and Preschoolers with Recurrent Wheezing

The infant or child presenting to the physician's office with persistent or recurrent wheezing during the first 2 years of life poses, often times, a diagnostic dilemma, and a therapeutic challenge. Until very recently, no guidelines were present to help the clinician navigate the very limited treatment options. The diagnosis of asthma in the very young is primarily difficult because of the lack of consistency of what is called asthma, and the failure to recognize the different phenotypes of asthma at different ages. Many classification and phenotypic descriptions have been proposed, but they continue to cause more confusion to already confused parents and perplexed physicians. Although these studies have provided much insight into the natural history of wheezy disorders, they have failed to affect clinical management to a large extent. Controversy persists as to when and why and how long inhaled corticosteroids (ICS) should be used in wheezy infants. Based on the current knowledge in this age group, ICS seems to be indicated in infants with multi-triggers wheeze, and in infants with a positive asthma predictive index. This article reviews the different phenotypic presentations of wheezy infant, the role and indications of ICS in this situation, and, finally, suggests a treatment plan based on the apparent cause of wheezing.

Advances in pediatric asthma in 2010: addressing the major issues

Last year's "Advances in pediatric asthma" concluded with the following statement: "If we can close these [remaining] gaps through better communication, improvements in the health care system and new insights into treatment, we will move closer to better methods to intervene early in the course of the disease and induce clinical remission as quickly as possible in most children." This year's summary will focus on recent advances in pediatric asthma that take steps moving forward as reported in Journal of Allergy and Clinical Immunology publications in 2010. Some of these recent reports show us how to improve asthma management through steps to better understand the natural history of asthma, individualize asthma care, reduce asthma exacerbations, and manage inner-city asthma and some potential new ways to use available medications to improve asthma control. It is clear that we have made many significant gains in managing asthma in children, but we have a ways to go to prevent asthma exacerbations, alter the natural history of the disease, and reduce health disparities in asthma care. Perhaps new directions in personalized medicine and improved health care access and communication will help maintain steady progress in alleviating the burden of this disease in children, especially young children.

Maternal Pre-Pregnancy Obesity and Recurrent Wheezing in Early Childhood

A number of studies have linked obesity with asthma in adults and children. Few longitudinal studies have evaluated the effect of maternal pre-pregnancy obesity on either asthma or early childhood respiratory morbidity, and these have not been in urban, nonwhite populations. We sought to determine whether pre-pregnancy obesity was associated with recurrent wheezing in an urban, nonwhite population. This study includes 1,191 children from the Boston Birth Cohort (1998-present) followed prospectively to a mean age of 3.0 ± 2.4 years with study visits aligned with the pediatric primary care schedule. Multivariate logistic regression was used to evaluate the associations of maternal pre-pregnancy obesity (body mass index ≥30) with recurrent wheezing (≥4 lifetime episodes). Secondary outcomes included log-transformed cord-blood immunoglobulin E (Phadia), and physician diagnoses of eczema and food allergy. Pre-pregnancy obesity was present in 20.7% of mothers. Of the 1,191 children, 60 (5%) developed recurrent wheezing. Children of obese mothers had an increased risk of recurrent wheezing (adjusted odds ratio, 95% confidence interval: 3.51, 1.68-7.32). These associations persisted even after adjustment for fetal growth status. In contrast, maternal obesity was not associated with eczema or food allergy, and was inversely associated with log cord-blood immunoglobulin E (β, 95% confidence interval: -0.34, -0.66 to -0.02). In this predominantly urban, multiracial/ethnic birth cohort, maternal pre-pregnancy obesity was associated with an increased risk of recurrent wheezing. This association was not explained by fetal growth or increased atopy. Maternal pre-pregnancy obesity is a prevalent risk factor for respiratory morbidity in this urban, nonwhite population.