- Acute, life-threatening upper airway obstruction due to infraglottic bacterial infection following a primary viral infection (typically parainfluenza or influenza)
- Historically high mortality rates of up to 20% in children; more recent experience suggests changing epidemiology resulting in a more atypical presentation and variable course (1) but which can still result in severe, acute, upper airway obstruction.
- Affects two major groups of patients in the pediatric age range:
- Those with a native intact airway
- Those with an artificial airway
- Often preceded by viral infection, such as influenza, parainfluenza, or respiratory syncytial virus
- Staphylococcus aureus is the most common bacteria identified (1).
- Diagnostic hallmarks on endoscopy: ulceration, pseudomembranes in the trachea with thick mucopurulent exudates and mucosal sloughing (1)
- System(s) affected: pulmonary
- Synonym(s): laryngotracheobronchitis; bacterial croup; pseudomembranous croup
- Incidence: 4 to 8 per 1 million children
- Peak incidence in children: fall and winter
- Mean age: 5 years (2)
- Infections in adolescents and adults have been reported.
Methicillin-resistant Staphylococcus aureus (MRSA) may contribute to changing epidemiology and virulence.
Etiology and Pathophysiology
- Methicillin-sensitive S. aureus (MSSA) accounted for 50% cases in Casazza series (2019) (1).
- Mixed respiratory
- Streptococcus pneumoniae
- In children with artificial airway, most common organisms are S. aureus, Haemophilus influenzae, S. pneumoniae, Pseudomonas aeruginosa, and other gram-negative organisms.
- Viral-induced injury to the respiratory epithelium in conjunction with localized immune impairment can predispose individuals to bacterial superinfection.
No known genetic predisposition
- Periods of increased seasonal activity of respiratory viruses
- Reports following tonsillectomy, adenoidectomy, with chronic tracheal aspiration, and with evidence of other concurrent infections, including sinusitis, otitis, pneumonia, or pharyngitis
- Standard precautions, with scrupulous attention to handwashing
- Vaccination against viruses that may predispose to bacterial tracheitis
Commonly Associated Conditions
- Consider anatomic abnormalities and foreign bodies as well as recent pharyngeal or laryngeal surgery.
- Predisposing: Down syndrome, immunodeficiency, subglottic hemangioma, tracheoesophageal fistula repair, tracheobronchomalacia
- More common in children with tracheostomy
- Viral coinfection may occur.
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