A 4-year-old unvaccinated child presents with high fever (40°C), neck stiffness, Kernig's and Brudzinski's signs, and petechial rash. CSF: WBC 1200/mm³ (90% PMN), protein 280 mg/dL, glucose 18 mg/dL (blood glucose 90 mg/dL). Gram stain shows Gram-negative diplococci. What is the most likely organism and the drug of choice?
- A Neisseria meningitidis; IV penicillin G or IV ceftriaxone ✓
- B Haemophilus influenzae type b; IV cefotaxime
- C Streptococcus pneumoniae; IV vancomycin + ceftriaxone
- D Listeria monocytogenes; IV ampicillin + gentamicin
Explanation
Gram-negative diplococci in CSF of a child with bacterial meningitis and petechial/purpuric rash (purpura fulminans) is characteristic of Neisseria meningitidis (meningococcal meningitis). The rash is due to meningococcal bacteremia causing endothelial damage and disseminated intravascular coagulation (DIC). N. meningitidis is exquisitely sensitive to penicillin G, which remains first-line when susceptibility is confirmed; IV ceftriaxone is equally effective and used empirically. Haemophilus influenzae type b (Hib) causes meningitis in unvaccinated children but the Gram stain would show Gram-negative coccobacilli. Streptococcus pneumoniae (Gram-positive diplococci) would require vancomycin + ceftriaxone empirically due to resistance. Listeria causes meningitis in neonates and immunocompromised patients, not typically in 4-year-olds.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.