From the Guidelines
Viral-induced wheeze in children is a significant risk factor for the development of asthma later in life, particularly in those with a family history of asthma, allergic sensitization, or early onset of wheezing episodes. According to the expert panel report 3 (EPR-3) guidelines for the diagnosis and management of asthma, children who experience recurrent episodes of wheezing triggered by respiratory viruses have a higher likelihood of developing persistent asthma 1. The relationship between viral-induced wheeze and asthma development is thought to be due to the damage caused by viral infections to the airway epithelium, promotion of airway inflammation, and interaction with genetic predispositions to create long-term changes in airway function and reactivity.
Key factors that increase the risk of asthma development in children with viral-induced wheeze include:
- Family history of asthma or allergies
- Early onset of wheezing episodes (before age 3)
- Allergic sensitization
- Frequent episodes of wheezing
Management of viral-induced wheeze in children typically involves:
- Bronchodilators like albuterol for acute episodes
- Consideration of intermittent or continuous inhaled corticosteroids for recurrent cases
- A 3-month trial of daily low-dose inhaled corticosteroids (such as fluticasone 50mcg twice daily) to assess response in children with frequent episodes 2
It is essential to note that not all children with viral-induced wheeze will develop asthma, and many outgrow these episodes by school age. Parents should be educated about avoiding smoke exposure and managing respiratory infections promptly to potentially reduce the risk of progression to persistent asthma. The Prevention of Early Asthma in Kids (PEAK) trial demonstrated that early recognition and treatment of children at increased risk of developing asthma can improve symptom control and reduce exacerbations, but may also have some side effects on linear growth 2.
From the Research
Viral Induced Wheeze and Asthma Risk
- Viral induced wheeze has been shown to increase the risk of asthma, with different viral species having varying impacts on the development of asthma 3.
- The major viral species causing wheezing in children include respiratory syncytial virus, rhinovirus, human metapneumovirus, and influenza viruses 3.
- Studies have also focused on the interaction between virus infection and other risk factors in the development of asthma, such as genetic factors or allergic sensitization 3, 4, 5.
Risk Factors and Interactions
- Pre-existing airway abnormalities contribute to early virus-induced symptoms, which usually remit in early childhood, whereas an interaction with airway inflammation causes exacerbations in asthma 4.
- The effect of early infections on the developing immune system is complex, with the successful maturation of the T-cell response influenced by genetic factors and the number of infections 4.
- The relative parts played by predisposition and immunomodulation by early infections in later development of asthma are still controversial, but are being resolved by detailed prospective studies 4, 5.
Treatment and Management
- High-dose inhaled salbutamol may interact with oral prednisolone in young, hospitalized children with first episode of rhinovirus-induced wheezing, but further trials are warranted 6.
- Adding salmeterol to an inhaled corticosteroid can lead to better symptomatic asthma control, but has no sustained effect on allergen-induced cellular bronchial inflammation 7.
- The addition of salmeterol to fluticasone produces a significant improvement in size selectivity of plasma protein permeation across the respiratory membrane, which may contribute to the improved clinical outcome seen in patients with allergic asthma 7.