Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features +++ Essentials of Diagnosis ++ Diffuse wheezing and tachypnea following upper respiratory symptoms in an infant (bronchiolitis) Epidemics in late fall to early spring (January–February peak) Hyperinflation on chest radiograph Detection of RSV antigen or nucleic acid in nasal secretions +++ General Considerations ++ Accounts for more than 70% of cases of bronchiolitis and 40% of cases of pneumonia Virus is ubiquitous in early childhood Outbreaks occur each year, and attack rates are high 60% of children are infected in the first year of life 90% by age 2 years Progressive severe pneumonia may develop in immunosuppressed patients Children with congenital heart disease with increased pulmonary blood flow, children with chronic lung disease (eg, cystic fibrosis), and premature infants younger than age 6 months (especially when they have chronic lung disease of prematurity) are also at higher risk for severe illness +++ Clinical Findings +++ Symptoms and Signs ++ Low-grade fever may be present Classic disease is bronchiolitis, characterized by Diffuse wheezing Variable fever Cough Tachypnea Difficulty feeding Cyanosis (in severe cases) Hyperinflation, crackles, prolonged expiration, wheezing, and retractions are present Liver and spleen may be palpable but not enlarged Apnea, poor feeding, and lethargy may be presenting manifestations, especially in premature infants, in the first few months of life Infection in older children is more likely to cause tracheobronchitis or upper respiratory tract infection +++ Differential Diagnosis ++ Bronchiolitis Parainfluenza, rhinovirus, and especially human metapneumovirus Chlamydial pneumonitis Cystic fibrosis Bacterial superinfection (neutrophilia) Pertussis (lymphocytosis) +++ Diagnosis +++ Laboratory Findings ++ Fluorescent antibody staining or ELISA Rapidly detects RSV antigen in nasal or pulmonary secretions Requires only several hours More than 90% sensitive and specific Real-time polymerase chain reaction (PCR) More sensitive than antigen testing but is more expensive Multiplexed to detect four or more viral respiratory pathogens in the same assay Rapid tissue culture methods Take 48 hours and have comparable sensitivity Require a carefully collected and handled specimen +++ Imaging ++ Diffuse hyperinflation and peribronchiolar thickening are most common Atelectasis and patchy infiltrates also occur in uncomplicated infection, but pleural effusions are rare Consolidation (usually subsegmental) occurs in 25% of children with lower respiratory tract disease +++ Treatment ++ Children who are very hypoxic or cannot feed because of respiratory distress must be hospitalized and given humidified oxygen as directed by oxygen saturation, and given tube or intravenous feedings Antibiotics, decongestants, and expectorants are of no value in routine infections a trial of bronchodilator therapy is given to determine response and is subsequently discontinued if there is no improvement. Racemic epinephrine occasionally works when β-agonists fail. This therapeutic trial should only be undertaken in a hospital setting and care taken to ... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth