This patient's clinical presentation is most consistent with bronchiolitis, an infection that occurs in the winter and is most commonly caused by respiratory syncytial virus (RSV). Patients typically have nasal congestion, rhinorrhea, coarse breath sounds, and wheezing with or without crackles. Other common features include a low-grade fever, increased work of breathing with accessory muscle use (eg, retractions), nasal flaring, and grunting. Respiratory symptoms may interfere with feeding and increase the risk of dehydration.
Bronchiolitis is generally diagnosed clinically. Classic features include an upper respiratory prodrome of rhinorrhea, nasal congestion, and cough, followed 2-3 days later by lower airway signs of wheezing and increased work of breathing. Antigen testing of nasal or pulmonary secretions (Choice A) or nucleic acid amplification testing is used to detect breakthrough respiratory syncytial virus (RSV) infection among infants who receive palivizumab prophylaxis.
Patients with respiratory distress, apnea, hypoxia, and/or dehydration should be hospitalized on contact and droplet precautions to prevent nosocomial spread of this extremely contagious virus. Therapy generally consists of supportive measures, such as intravenous fluids, nasal bulb suctioning, and/or humidified oxygen. Inhaled bronchodilators used to be recommended, but this is no longer the case as current evidence shows that they do not reduce illness duration, admission rates, or length of hospital stay.
Antibiotics have no role in the treatment of bronchiolitis unless there is concern for coexisting bacterial pneumonia (eg, high fever, focal crackles on auscultation, consolidation on chest x-ray).
Systemic corticosteroids are not recommended for first-time bronchiolitis due to the lack of evidence of clinical effect. Corticosteroids can be considered in patients with recurrent wheezing or asthma exacerbation.
RSV is associated with the development of recurrent wheezing in up to 30% of patients. Patient should be advised to avoid other triggers of airway reactivity, particularly exposure to secondhand cigarette smoke.