A 19-year-old student presents with acute meningitis: fever, neck stiffness, photophobia, and petechial rash. CSF shows: WBC 1800 (predominantly neutrophils), glucose 1.8 mmol/L (blood glucose 5.2 mmol/L), protein 2.4 g/L. Gram stain shows Gram-negative diplococci. What is the empirical antibiotic and corticosteroid strategy?

• A IV ceftriaxone alone; corticosteroids are contraindicated in bacterial meningitis
• B IV ampicillin + gentamicin; defer dexamethasone pending culture
• C IV vancomycin + ceftriaxone; avoid dexamethasone as it reduces vancomycin penetration
• D IV ceftriaxone 2 g every 12 hours + IV dexamethasone 0.15 mg/kg every 6 hours for 4 days, started before or with first antibiotic dose ✓

Explanation

Bacterial meningitis (here Neisseria meningitidis given Gram-negative diplococci and petechiae) is treated with IV ceftriaxone. Adjunctive dexamethasone (0.15 mg/kg 6-hourly for 4 days) reduces neurological sequelae and mortality, particularly in pneumococcal meningitis, and should be started before or with the first antibiotic dose per Cochrane evidence and IDSA guidelines. The concern about dexamethasone reducing vancomycin CNS penetration applies to pneumococcal meningitis with cephalosporin resistance; in meningococcal disease ceftriaxone covers adequately. Ampicillin-gentamicin is not first-line for meningococcal disease.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.