SUMMARY
Bronchiolitis is an acute infection of the lower respiratory tract affecting infants and young children, with Respiratory Syncytial Virus (RSV) being the most common pathogen. Bronchiolitis is generally a mild disease, but may present with severe signs and symptoms requiring hospitalization. Risk factors including prematurity, bronchopulmonary dysplasia, immunodeficiency and congenital heart defects may predispose patients to develop a severe disease. The diagnosis should be based on clinical evaluation, without supportive radiographic and laboratory studies. Etiological diagnosis may be helpful to decrease the hospital transmission of virus and to avoid inappropriate use of antibiotics.The mainstay of therapy for bronchiolitis is supportive care, which should be directed at maintaining adequate oxygenation, ensuring a proper respiratory toilet, and meeting the requirements of fluids and nutrition. The use of nebulized hypertonic saline should be limited to hospitalized patients. Severe respiratory failure may require mechanical ventilatory support. Neither corticosteroids nor antibiotics offer consistent benefit in the treatment of bronchiolitis, and thus should not be used. A trial of a bronchodilator may be appropriate, but should be continued exclusively if a prompt favorable response occurs. Effective interventions to prevent the spread of RSV infection include hand washing or disinfection by caregivers and contact isolation. The use of palivizumab, a monoclonal antibody directed against RSV, is a safe prophylactic option, but should be restricted to children at high-risk for severe RSV disease, during the epidemic period. Current evidence suggests that early RSV bronchiolitis predisposes children to recurrent wheezing and asthma in the first decade of life.