Practice Essentials
Except in patients with a tracheostomy or endotracheal tube, bacterial tracheitis is an uncommon infectious cause of acute upper airway obstruction. It is currently more prevalent than acute epiglottitis in children who have received Haemophilus type B vaccine. Patients may present with crouplike symptoms, such as barking cough, stridor, and fever; however, patients with bacterial tracheitis do not respond to standard croup therapy (racemic epinephrine) and instead require treatment with antibiotics and may experience acute respiratory decompensation. [1, 2, 3, 22]
Pathophysiology
Bacterial tracheitis is a diffuse inflammatory process of the larynx, trachea, and bronchi with adherent or semiadherent mucopurulent membranes within the trachea. The major site of disease is at the cricoid cartilage level, the narrowest part of the trachea. Acute airway obstruction may develop secondary to subglottic edema and sloughing of epithelial lining or accumulation of mucopurulent membrane within the trachea. Signs and symptoms are usually intermediate between those of epiglottitis and croup. [4, 5]
Bacterial tracheitis may be more common in the pediatric patient because of the size and shape of the subglottic airway. The subglottis is the narrowest portion of the pediatric airway, assuming a funnel-shaped internal dimension. In this smaller airway, relatively little edema can significantly reduce the diameter of the pediatric airway, increasing resistance to airflow and work of breathing. With appropriate airway support and antibiotics, most patients improve within 5 days.
Although the pathogenesis of bacterial tracheitis is unclear, mucosal damage or impairment of local immune mechanisms due to a preceding viral infection, an injury to the trachea from recent intubation, or trauma may predispose the airway to invasive infection with common pyogenic organisms.
Epidemiology
Frequency
United States
Tan and Manoukian reported that 500 children were hospitalized for croup at one pediatric hospital over a 32-month period. [6] Approximately 98% had viral croup, and 2% had bacterial tracheitis. Cases usually occur in the fall or winter months, mimicking the epidemiology of viral croup.
A study that described the frequency and severity of complications in hospitalized children younger than 18 years with seasonal influenza (during 2003-2009) and 2009 pandemic influenza A(H1N1) (during 2009-2010) reported that out of 7293 children hospitalized with influenza, less than 2% had complications from tracheitis. However, along with other rare complications, tracheitis was associated with a median hospitalization duration of more than 6 days, with 48%-70% of children requiring intensive care. [7]
International
According to a recent study, bacterial tracheitis remains a rare condition, with an estimated incidence of approximately 0.1 cases per 100,000 children per year. [8]
Mortality/Morbidity
The predominant morbidity and mortality is related to the potential for acute upper airway obstruction and induced hypoxic insults. The mortality rate has been estimated at 4-20%. In the acute phase, patients generally do well if the airway is adequately managed and if antibiotic therapy is promptly initiated.
Sex
In most epidemiologic studies, male cases are preponderant. Gallagher et al reported a male-to-female predominance of 2:1. [9]
Age
Bacterial tracheitis may occur in any pediatric age group. Gallagher et al reported 161 cases of patients younger than 16 years. [9] The age range was from 3 weeks to 16 years, with a mean age of 4 years. This is in contrast to viral laryngotracheobronchitis, which occurs in patients aged 6 months to 3 years.
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Steeple sign.
