Preschool asthma after bronchiolitis in infancy.

Area of Science:

• Pediatrics
• Infectious Diseases
• Allergy and Immunology

Background:

• Respiratory syncytial virus (RSV) is a primary cause of wheezing illness in infants younger than six months.
• Previous studies suggest a link between infant wheezing and later asthma development.
• The specific impact of viral etiology on long-term asthma risk following early-life bronchiolitis requires further investigation.

Purpose of the Study:

• To evaluate the long-term outcomes, specifically asthma development, in children hospitalized for bronchiolitis before six months of age.
• To determine the influence of viral etiology, particularly RSV versus non-RSV infections, on the risk of developing asthma.
• To identify early-life risk factors associated with asthma in this cohort.

Main Methods:

• A cohort of 205 infants hospitalized for bronchiolitis at <6 months of age was followed.
• Viral aetiology was determined upon admission using antigen detection or PCR.
• Long-term follow-up data on asthma were collected through structured questionnaires and telephone interviews at a mean age of 6.5 years.

Main Results:

• Viral aetiology was identified in 97% of bronchiolitis cases.
• Current asthma was diagnosed in 12.7% of children, with a significantly lower prevalence (8.2%) in former RSV patients compared to non-RSV patients (24%, p=0.01).
• Independent early-life risk factors for asthma included atopic dermatitis, non-RSV bronchiolitis, and maternal asthma.

Conclusions:

• The risk of developing asthma is significantly lower following RSV bronchiolitis compared to bronchiolitis caused by other viruses in infants hospitalized before six months of age.
• Early-life factors such as atopic dermatitis and maternal asthma history are significant predictors of childhood asthma.
• Understanding the viral cause of infant bronchiolitis is crucial for assessing long-term asthma risk.