A 10-year-old boy is brought to the emergency department due to respiratory distress. Over the past 6 hours, rapid, noisy breathing has progressively developed. Temperature is 40.1 C (104.2 F), blood pressure is 105/75 mm Hg, pulse is 120/min, and respirations are 32/min. Examination shows inspiratory stridor and supraclavicular retractions. Lateral neck x-ray is shown in the exhibit.
The patient is admitted to the hospital, and blood cultures are obtained. If blood cultures are positive, which of the following would most likely be seen on Gram stain?

Question

A 10-year-old boy is brought to the emergency department due to respiratory distress.  Over the past 6 hours, rapid, noisy breathing has progressively developed.  Temperature is 40.1 C (104.2 F), blood pressure is 105/75 mm Hg, pulse is 120/min, and respirations are 32/min.  Examination shows inspiratory stridor and supraclavicular retractions.  Lateral neck x-ray is shown in the exhibit.  
The patient is admitted to the hospital, and blood cultures are obtained.  If blood cultures are positive, which of the following would most likely be seen on Gram stain?

Quizplus · Accepted Answer

11ec160b_3826_5406_9249_47ab964a75e0_MD0001_00 This child has high fever and rapidly progressive respiratory distress (eg, retractions, stridor) with a swollen epiglottis ("thumbprint sign") on lateral neck x-ray. These findings are consistent with epiglottitis, an uncommon but potentially fatal infection of the upper airway. Progressive epiglottic inflammation can also cause dysphagia and drooling with pooled oral secretions, and the potential for acute airway obstruction makes rapid diagnosis critical. Epiglottitis once occurred mainly in young children (age ~3) due to high rates of infection with Haemophilus influenzae type b (Hib). With widespread vaccination against Hib, rates of epiglottitis dramatically declined; now, adults and school-aged children are more commonly affected. H influenzae remains the most common pathogen, including Hib (due to waning immunity) and nontypeable strains for which there are no vaccines. Hib epiglottitis is often associated with concomitant bacteremia, and Gram stain would show gram-negative coccobacilli consistent with H influenzae. (Choices A and C) Gram-negative cocci (eg, Moraxella in pairs) and rods (eg, Klebsiella in pairs or short chains) are rare causes of epiglottitis. In addition, associated bacteremia is far more likely when Hib is the causative pathogen due to its highly virulent capsule. (Choices D and E) Gram-positive organisms (eg, Streptococcus pneumoniae in chains, Staphylococcus aureus in clusters) are less common causes of epiglottitis. Although the number of epiglottitis cases caused by these organisms (particularly S pneumoniae) has increased since widespread vaccination against Hib, the combined strains of H influenzae still occur more frequently than any other organism. Educational objective: Epiglottitis causes rapidly progressive respiratory distress and a swollen epiglottis ("thumbprint sign") on lateral neck x-ray. The most common pathogen is Haemophilus influenzae (ie, type b, nontypeable strains), a gram-negative coccobacillus that often causes concomitant bacteremia. __________ References: Epiglottitis. (http://www.ncbi.nlm.nih.gov/pubmed/28613691)

A 10-Year-Old Boy Is Brought to the Emergency Department Due