Bronchiolitis Age Range
Bronchiolitis is defined as affecting children from 1 month through 23 months of age (less than 2 years), according to the American Academy of Pediatrics clinical practice guidelines. 1
Standard Age Definition
- The AAP guidelines specifically target children aged 1 month to 23 months for bronchiolitis diagnosis and management 1
- The older 2006 AAP guideline defined the population as infants less than 2 years of age 2
- Most hospitalizations occur in infants less than 1 year old, with bronchiolitis being the most common cause of hospitalization in this age group 1
Age-Specific Clinical Considerations
Neonates (Under 1 Month)
- Infants under 1 month with bronchiolitis-like symptoms require special consideration due to higher risk of severe disease and apnea 1
- These neonates fall outside the standard AAP guideline recommendations and need individualized assessment 1
High-Risk Younger Infants (Under 12 Weeks)
- Infants younger than 12 weeks are at significantly higher risk for severe disease 2, 1
- Age 1-12 months is associated with increased work of breathing, including tachypnea, nasal flaring, and intercostal retractions 1
- Higher risk of apnea exists, particularly in those younger than 1 month and premature infants 1
Older Infants (12-24 Months)
- Children aged 12-24 months typically present with rhinitis and cough that may progress to wheezing and rales 1
- These older infants generally compensate better for increased respiratory effort compared to younger infants 1
Epidemiological Context
- Approximately 90% of children are infected with RSV within the first 2 years of life, making this the critical age window 1, 3
- Bronchiolitis leads to more than 90,000 hospitalizations annually in the United States 1, 3
Important Caveats
- Children outside the 1-24 month age range may develop bronchiolitis-like illnesses but may have different clinical presentations, management needs, and outcomes 1
- The guidelines specifically exclude children with immunodeficiencies, underlying respiratory illnesses, neuromuscular disease, or hemodynamically significant congenital heart disease from general management recommendations 1