Rosh Pediatrics Practice Exam

In a case of bacterial tracheitis presenting with high fever and stridor, which pathogen is most likely responsible?

1. Haemophilus influenzae type b

2. Parainfluenza virus

3. Pseudomonas aeruginosa

4. Staphylococcus aureus

The correct answer is: Staphylococcus aureus

In cases of bacterial tracheitis, especially when presenting with high fever and stridor, Staphylococcus aureus is the most commonly implicated pathogen. This condition typically arises following a viral upper respiratory infection, which can cause inflammation and disruption of the tracheal lining, leading to secondary bacterial infection. Staphylococcus aureus, particularly strains that produce toxins like toxic shock syndrome toxin, can result in severe respiratory distress and the characteristic symptoms of high fever and stridor due to airway obstruction from purulent secretions. The other pathogens listed, while they can cause respiratory illnesses, are less frequently associated with bacterial tracheitis. Haemophilus influenzae type b primarily causes epiglottitis and is not the main culprit in tracheitis. Parainfluenza virus is a common viral agent leading to croup, but it does not directly cause bacterial tracheitis. Pseudomonas aeruginosa is typically found in cases involving previous respiratory therapy or in immunocompromised patients, but it is not the most common pathogen in uncomplicated bacterial tracheitis cases. Therefore, Staphylococcus aureus is the key pathogen responsible in this clinical scenario.