What is the most likely causative organism in a child presenting with severe epiglottitis, characterized by difficulty swallowing, drooling, and a toxic appearance, with a high fever (hyperthermia)?

H. Influenzae Type B is the Most Likely Causative Organism

This child presents with classic acute epiglottitis caused by Haemophilus influenzae type B, characterized by the pathognomonic "tripod" positioning (sitting upright, leaning forward with neck extended), drooling, toxic appearance, and high fever. 1, 2, 3

Clinical Reasoning

Classic Presentation of Bacterial Epiglottitis

The clinical picture is unmistakable for acute epiglottitis:

• Rapid progression from minimal symptoms (12-hour history of cough/rhinorrhea) to severe airway compromise with dysphagia and respiratory distress 1, 4
• Toxic appearance with high fever (39-40°C) distinguishes this from viral croup 2, 3
• Tripod positioning (sitting upright, mouth open, neck extended) with drooling represents the child's attempt to maintain airway patency 3, 4
• Dysphagia (difficulty swallowing food) indicates supraglottic inflammation 2, 5

Why H. Influenzae Type B is the Answer

H. influenzae type B accounts for >95% of invasive epiglottitis cases in children, making it by far the most likely organism. 1, 2, 4 The organism produces capsular polysaccharide (polyribosyl-ribitol phosphate) that enables invasive disease with bacteremia, which is a prominent feature of epiglottitis. 2

Why NOT the Other Options

Parainfluenza virus causes viral croup (acute subglottic laryngitis), which presents differently:

• Gradual onset over 2-3 days with prodromal URI symptoms 5
• Barking "seal-like" cough (not present here) 5
• Subglottic narrowing causing inspiratory stridor 5
• Child typically does NOT appear toxic 5
• Responds to corticosteroids without antibiotics 5

Staphylococcus aureus is an uncommon cause of epiglottitis:

• Accounts for <5% of epiglottitis cases 2
• More commonly causes tracheitis or post-viral bacterial superinfection 6
• Does not fit the classic epidemiology or presentation pattern 1, 4

Critical Management Considerations

Immediate Airway Management Priority

Do NOT attempt to visualize the epiglottis or obtain throat swabs in the emergency setting - this can precipitate complete airway obstruction and death. 7 Blood cultures are the preferred diagnostic specimen and should be obtained only after airway security is established. 7, 2

Approximately 90% of children with H. influenzae type B epiglottitis require endotracheal intubation for airway protection. 1, 4 Five deaths and four cases of permanent neurological damage occurred in one series due to airway obstruction prior to hospital arrival. 4

Antibiotic Selection

Third-generation cephalosporins (cefotaxime or ceftriaxone) are the empiric antibiotics of choice because 57% of H. influenzae type B strains produce β-lactamases and are ampicillin-resistant. 1, 2, 4 Treatment should be initiated immediately after securing the airway and obtaining blood cultures. 2, 3

Diagnostic Confirmation

• Blood cultures grow H. influenzae type B in 95% of cases 1, 3
• Urine latex agglutination for H. influenzae type B capsular antigen can provide rapid diagnosis in up to 90% of cases 2, 3
• Lateral neck radiograph may show the classic "thumb sign" (swollen epiglottis), but should NOT delay airway management 3

Common Pitfalls to Avoid

• Never examine the throat with a tongue depressor in suspected epiglottitis - this can trigger laryngospasm and complete obstruction 7
• Do not delay airway management for diagnostic procedures - the disease can progress to complete obstruction within hours 1, 4
• Do not confuse with viral croup - the toxic appearance, drooling, and tripod positioning distinguish epiglottitis from the more common viral subglottic laryngitis 5
• Do not use ampicillin alone as empiric therapy given high rates of β-lactamase production 1, 4