Title:Respiratory Syncytial Virus is the Most Common Causative Agent of Viral
Bronchiolitis in Young Children: An Updated Review
Volume: 19
Issue: 2
Author(s): Kam L. Hon*, Alexander K. C. Leung, Alex H.C. Wong, Amrita Dudi and Karen K.Y. Leung
Affiliation:
- Department of Paediatrics and Adolescent Medicine, The Hong Kong Children’s Hospital, Kowloon Bay, Hong Kong
Keywords:
Bronchiolitis, viral, respiratory syncytial virus, RSV, wheezing, beta-agonists, nebulized racemic epinephrine, hypertonic saline, corticosteroids.
Abstract:
Background: Viral bronchiolitis is a common condition and a leading cause of hospitalization
in young children.
Objective: This article provides readers with an update on the evaluation, diagnosis, and treatment
of viral bronchiolitis, primarily due to RSV.
Methods: A PubMed search was conducted in December 2021 in Clinical Queries using the key
terms "acute bronchiolitis" OR “respiratory syncytial virus infection”. The search included clinical
trials, randomized controlled trials, case control studies, cohort studies, meta-analyses, observational
studies, clinical guidelines, case reports, case series, and reviews. The search was restricted to
children and English literature. The information retrieved from the above search was used in the
compilation of this article.
Results: Respiratory syncytial virus (RSV) is the most common viral bronchiolitis in young children.
Other viruses such as human rhinovirus and coronavirus could be etiological agents. Diagnosis
is based on clinical manifestation. Viral testing is useful only for cohort and quarantine purposes.
Cochrane evidence-based reviews have been performed on most treatment modalities for RSV and
viral bronchiolitis. Treatment for viral bronchiolitis is mainly symptomatic support. Beta-agonists
are frequently used despite the lack of evidence that they reduce hospital admissions or length of
stay. Nebulized racemic epinephrine, hypertonic saline and corticosteroids are generally not effective.
Passive immunoprophylaxis with a monoclonal antibody against RSV, when given intramuscularly
and monthly during winter, is effective in preventing severe RSV bronchiolitis in high-risk
children who are born prematurely and in children under 2 years with chronic lung disease or
hemodynamically significant congenital heart disease. Vaccines for RSV bronchiolitis are being
developed. Children with viral bronchiolitis in early life are at increased risk of developing asthma
later in childhood.
Conclusion: Viral bronchiolitis is common. No current pharmacologic treatment or novel therapy
has been proven to improve outcomes compared to supportive treatment. Viral bronchiolitis in early
life predisposes asthma development later in childhood.
