Respiratory Syncytial Virus Infection in Children

Clinical Presentation and Epidemiology

The American Academy of Pediatrics notes that RSV infection typically presents with 2-4 days of upper respiratory symptoms, including rhinorrhea, congestion, and fever, before progressing to lower respiratory tract involvement, affecting approximately 90% of children within the first 2 years of life 1, 2
The initial rhinorrhea is typically clear and watery, accompanied by sneezing and nasal congestion, representing the hallmark early presentation of RSV infection 3, 4
RSV demonstrates clear seasonal patterns, with peak incidence occurring between December and March in North America, though regional variations exist 1, 5
The Centers for Disease Control and Prevention (CDC) reports that RSV is the most common cause of lower respiratory tract infection in children under 2 years of age 1, 6

Other viral causes of rhinorrhea in children include rhinoviruses, parainfluenza, influenza, adenoviruses, and human metapneumovirus, but RSV remains the most common 3, 4, 7
The clinical presentation of prominent rhinorrhea followed by lower respiratory symptoms is indistinguishable between these viral etiologies, making RSV the most likely diagnosis based on prevalence alone 6

Infants 1-12 months are more likely to progress rapidly from rhinorrhea to increased work of breathing, including tachypnea, nasal flaring, and intercostal retractions 6
The American Academy of Pediatrics recommends that premature infants, children with chronic lung disease, and those with hemodynamically significant congenital heart disease receive special attention when RSV rhinorrhea develops, as they are at highest risk for severe disease 2, 8
Palivizumab prophylaxis provides a 55% reduction in RSV-related hospitalization in high-risk infants 8

Infants under 12 weeks have the highest risk of severe disease, and premature infants (especially ≤35 weeks gestation) are at increased risk, according to the American Academy of Pediatrics guidelines 9
Chronic lung disease requiring oxygen, bronchodilators, diuretics, or corticosteroids within 6 months, and hemodynamically significant congenital heart disease, are risk factors for severe disease, as stated by the American Academy of Pediatrics 9
Neuromuscular disorders impairing secretion clearance, and immunocompromised states (profound lymphopenia <100 cells/mm³), are associated with an increased risk of progression to lower respiratory tract disease, as reported by the American Academy of Pediatrics 10, 11
During RSV season (November-March in North America), it is recommended to assume RSV when an infant <1 year presents with rhinorrhea, according to the American Academy of Pediatrics guidelines 9

The American Academy of Pediatrics recommends assessing for progression to lower respiratory tract disease by monitoring respiratory rate, work of breathing, and oxygen saturation, and risk stratifying based on age, prematurity history, underlying cardiopulmonary disease, and immunocompromised status 9, 10, 11