A 5-month-old full-term female infant presents to your office with 3 days of fever and cough. On examination, you note a frequent wet cough and appreciate bilateral wheezes. Pulse oximetry reveals a normal oxygen saturation. You reassure the mom that her daughter has bronchiolitis and needs supportive care only (Figure 48-1). She agrees to follow up with you in 1 to 2 days.

Bronchiolitis is inflammation of the bronchioles typically caused by a viral illness that frequently affects young children.¹

Respiratory Syncytial Virus (RSV) or lower respiratory tract infection (LRTI).

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  Most common lower respiratory tract infection in children less than 1 year of age.¹

  
  
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  Annual hospitalizations for bronchiolitis account for greater than half a billion dollars in health care expenditures.²

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  Viral etiology, most frequently RSV.

  
  
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  Other viruses implicated include influenza, parainfluenza, adenovirus, and human metapneumovirus.

  
  
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  Inflammation, edema, and necrosis of epithelial cells lining bronchioles (Figure 48-1).

  
  
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  Leads to increased mucus production and bronchospasm.

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  Up to 90 percent of infants will have had an RSV infection by the age of 2 years.¹

  
  
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  Infants with exposure to child care center populations, school-aged siblings, and smoke are at higher risk for developing bronchiolitis.³

  
  
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  Risk factors for severe disease include:

  
  
  
  
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    Prematurity of less than 35 weeks gestation.

    
    
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    Chronic lung disease or congenital airway malformations.

    
    
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    Cyanotic congenital heart disease.

    
    
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    Severe neuromuscular disease.

    
    
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    Immunocompromised state.⁴