Controversies in the management of preschool viral wheeze

The need to differentiate between adults and children when treating severe asthma

Severe asthma at all ages is heterogeneous incorporating several phenotypes that are distinct in children and adults, however, there are also numerous similar features including the limitation that they may not remain stable longitudinally. Severe asthma in both children and adults is characterized by eosinophilic airway inflammation and evidence of airway remodeling. In adults, targeting eosinophilia with anti-IL-5 antibody therapy is very successful, resulting in the recommendation that sputum eosinophils should be used to guide treatment. In contrast, data for the efficacy of blocking IL-5 remain unavailable in children. However, its effectiveness is uncertain since many children with severe asthma have normal blood eosinophils and the dominance of Th2-mediated inflammation is controversial. Approaches that have revealed gene signatures and biomarkers such as periostin that are specific to adult disease now need to be adopted in children to identify effective pediatric specific therapeutics and minimize the extrapolation of adult therapeutics to children.

Obstruktive Atemwegserkrankungen

In den folgenden Abschnitten werden die verschiedenen Formen der obstruktiven Atemwegserkrankungen erläutert, die je nach Alter, prädisponierenden Risikofaktoren und auch je nach Art der Auslöser verschiedenartige Ausprägungen und Verlaufsformen (Phänotypen) annehmen können.

Corticosteroids in respiratory diseases in children

We review recent advances in the use of corticosteroids (CS) in pediatric lung disease. CS are frequently used, systemically or by inhalation. Their mechanisms of action in pulmonary diseases are ill defined. CS exert direct inhibitory effects on many inflammatory cells through genomic mechanisms. There is a time lag before clinical response, and the washout of effects is also prolonged. Prompt relief in some conditions, such as croup, may be related to airway mucosal vasoconstriction through a nongenomic mechanism. CS have proven beneficial roles in the treatment of asthma, croup, allergic bronchopulmonary aspergillosis, and subglottic hemangioma. In some conditions, such as bronchiolitis, cystic fibrosis, and bronchopulmonary dysplasia, their use is controversial and is not recommended routinely. In other conditions, such as tuberculosis, interstitial lung disease, acute lung aspiration, and acute respiratory distress syndrome, CS are often used empirically despite the lack of clear evidence of their benefit. New drug regimens, including the more flexible use of inhaled corticosteroids and long-acting β-agonists in asthma, the lack of efficacy of oral corticosteroids in preschool children with acute wheeze, the severe complications of systemic dexamethasone used to prevent bronchopulmonary dysplasia and thus more restricted use, and the beneficial effect of pulse high-dose intravenous methylprednisolone in patients with allergic bronchopulmonary aspergillosis or cystic fibrosis are among the major recent developments. There is concern about adverse effects, especially growth and adrenal suppression, induced by systemic CS in children. These have been reduced, but not eliminated, with the use of the inhaled route. The benefits must be weighed against the potential detrimental effects.

Anti-inflammatory drug therapy in asthma

Asthma is a disease with chronic inflammation of the airways and and-inflammatory treatment is a logical treatment. Inhaled corticosteroids [ICS] remain the cornerstone of anti-inflammatory therapy in recent international guidelines. Asthma cannot be cured by any medication: if the drug is discontinued, the disease manifestations return. This has been proven at all ages. In preschool children the diagnosis of asthma is difficult to establish. In this heterogeneous group ICS or leukotriene receptor antagonists [LTRA] are just as effective as placebo; in the future it will hopefully be possible to describe characteristics of responders. LTRA are an alternative in mild asthma, especially when mono-triggered viral related wheeze is present. Theophylline is effective and also has bronchodilatory properties, which need to be balanced against the relatively frequent side effects. The working mechanisms of anti-inflammatory asthma medications including ICS, LTRA, cromones, macrolides and theophylline are described.

Early respiratory infections and asthma among New York City Head Start children

BACKGROUND

Respiratory infections in neonates have been found to predict wheeze among young children. We hypothesized that among preschool children from low-income minority communities in New York City, current asthma would be associated with a history of respiratory infection in the first few months after their birth.

METHODS

We asked parents of children in New York City Head Start centers (preschool programs for children of low-income families) to respond to a questionnaire covering demographic factors, lifestyle, home environment, and health history, including a detailed history of respiratory conditions. We used logistic regression to model the association of asthma and asthma severity with history of respiratory infections, controlling for gender, ethnicity, family history of asthma, and other factors.

RESULTS

Among 1,022 children (mean age 4+/- 0.6 years) whose parents provided information about their health history, 359 (35%) met our criteria for asthma. Overall, 22% had had a cold by 6 months and 17% an ear infection by 8 months of age. In multivariable models, children with asthma had had more colds (OR = 2.8, 95% confidence interval [CI] 1.4-6.0) and ear infections (OR = 3.4, 95% CI 1.7-6.9) in the past year than other children. Associations of respiratory infections with emergency department use for asthma (as a measure of severity) were similar. In models that did not control for infections in the past year, ages at first cold and first ear infection were associated with asthma and emergency department visits in the past year.

CONCLUSIONS

In this sample of preschool children, respiratory infections were common and were associated with asthma and health care utilization for asthma exacerbations. If these findings are confirmed, preventive measures among children who develop such infections at a very early age should be explored to help reduce the burden of asthma in this age group.