A 4-month-old infant presents with fever, irritability, and a full fontanelle. CSF analysis: glucose 15 mg/dL (blood glucose 80 mg/dL), protein 280 mg/dL, WBC 1200 cells/mm³ (95% neutrophils). Gram stain shows Gram-negative diplococci. The most appropriate empirical antibiotic regimen while awaiting sensitivity is:

• A Ampicillin plus gentamicin
• B Vancomycin plus ceftriaxone plus dexamethasone
• C Ceftriaxone alone
• D Ceftriaxone plus dexamethasone ✓

Explanation

Gram-negative diplococci in CSF of an infant strongly suggest Neisseria meningitidis (meningococcal meningitis). Ceftriaxone is the drug of choice for meningococcal and pneumococcal meningitis. Dexamethasone (0.15 mg/kg every 6 hours for 4 days) given before or with the first antibiotic dose reduces neurological sequelae (particularly hearing loss) in bacterial meningitis caused by H. influenzae and S. pneumoniae, and is also used for meningococcal meningitis. Vancomycin is added when pneumococcal meningitis with penicillin resistance is suspected; Gram-negative diplococci make this less likely.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.