Description

Acute life-threatening bacterial infection consisting of cellulitis and edema of the epiglottis, aryepiglottic folds, arytenoids, and hypopharynx, resulting in narrowing of the glottic opening and airway obstruction; also known as supraglottitis

Epidemiology

• Epiglottitis caused by Haemophilus influenzae type B occurs most often between the ages of 1 and 7 years (overall range: infancy to adulthood).
• Epiglottitis and other invasive disease secondary to H. influenzae type B have been reduced by 99% since the introduction of the conjugate vaccines in 1987 (approved for use at 15 months) and 1990 (approved for use at 2, 4, and 6 months).
• Nontypeable H. influenzae now appears to be a more common cause of invasive disease than type B.
• Year-round occurrence
• All geographic areas
• Can have secondary cases in households or child care centers
• May be more frequent in children with sickle cell anemia, asplenia, immunoglobulin defects, or hematologic malignancies (e.g., leukemia)
• Increasing ratio of adult to pediatric cases

General Prevention

• Universal immunization with H. influenzae type B capsular polysaccharide conjugate vaccines at 2 and 4 months (potential dose at 6 months, depending on the vaccine), with booster at 12 to 15 months
• Control measures:
  • Prophylaxis for H. influenzae type B index case and susceptible children in household and child care setting and intimate contacts with the assistance of infection control
  • Rifampin: 20 mg/kg/24 h in single dose for 4 days

Pathophysiology

• Edema of the supraglottic structures (uvula, aryepiglottic folds, arytenoids, epiglottis, and vocal cords) that reduces the airway aperture
• Respiratory arrest can be caused by airway obstruction, aspiration of oropharyngeal secretions, or mucous plugging.

Etiology

• H. influenzae, nontypeable and type B (type B accounted for up to 90% of cases prior to the introduction of H. influenzae type B vaccine)
• Streptococcus pneumoniae
• Streptococcus pyogenes (group A β-hemolytic Streptococcus)
• Staphylococcus aureus
• Groups C and G β-hemolytic Streptococcus
• Candida albicans may be an etiologic agent in immunocompromised patients and those receiving prolonged corticosteroid treatment.
• Pasteurella multocida has been implicated in a few cases after exposure to nasopharyngeal secretions from a cat.
• Other rare isolates: Moraxella catarrhalis, Klebsiella pneumoniae, Neisseria meningitidis, Pseudomonas species, Histoplasma
• Bacterial superinfection of viral infections including herpes simplex, parainfluenza, varicella, Epstein-Barr
• Varicella can cause primary infection or lead to a secondary infection, often with S. pyogenes.
• Noninfectious etiologies include thermal injuries, trauma, and caustic ingestions.