Bronchiolitis

Bronchiolitis is a clinical syndrome of respiratory distress commonly triggered by a viral infection of the lower airways in children below 24 months of age. Typically, children have a viral prodrome with upper respiratory symptoms (e.g., rhinorrhea, cough), followed by lower respiratory symptoms which may include tachypnea, wheezing, crackles or rales, and increased work of breathing (e.g., use of accessory muscles, nasal flaring, and/or grunting). Lower respiratory symptoms generally develop by around day 2–3 of illness, peak on days 3–5, and then resolve within a week, though the cough may linger for several weeks. Clinical severity of bronchiolitis can vary, from those who can be observed outpatient, to those who require mechanical ventilation in the intensive care unit (ICU). However, patients with hemodynamically significant congenital heart disease, immunodeficiency, neuromuscular weakness, chronic lung disease, prematurity, and complex medical conditions are at risk of more severe disease. Treatment is supportive. In the majority of cases, children with bronchiolitis are expected to have a full recovery.