A 5-year-old girl from Mumbai presents with a 3-day history of fever, headache, and vomiting. On day 2, her mother noticed a petechial rash on her trunk and lower limbs that does not blanch on pressure. On examination, temperature is 39.2°C, she is irritable with neck stiffness and positive Kernig sign. Blood pressure is 95/60 mmHg (low for age), capillary refill time 3 seconds. A lumbar puncture is performed urgently. CSF shows: cell count 680/μL (80% neutrophils), protein 150 mg/dL, glucose 32 mg/dL (serum glucose 105 mg/dL), Gram stain shows Gram-negative diplococci. Blood culture is sent. What is the most likely organism and the immediate management priority?

Explanation

## Clinical Diagnosis **Key Point:** The combination of **non-blanching petechial rash** + meningitis + **Gram-negative diplococci** on CSF Gram stain is pathognomonic for **meningococcal meningitis** caused by *Neisseria meningitidis*. ## Organism Identification | Feature | *N. meningitidis* | *S. pneumoniae* | *H. influenzae* | *E. coli* K1 | |---------|-------------------|-----------------|-----------------|-------------| | **Gram stain** | Gram-negative diplococci | Gram-positive diplococci | Gram-negative coccobacillus | Gram-negative rod | | **Rash** | Non-blanching petechiae/purpura (pathognomonic) | Absent or blanching | Absent | Absent | | **Age group** | Any age; peak 5–14 yrs | Any age; peak <5 yrs | <5 yrs (pre-vaccine era) | Neonates/infants | | **CSF glucose** | Low (often <20 mg/dL) | Low | Low | Low | **Clinical Pearl:** Non-blanching petechial or purpuric rash in a febrile child with meningitis = meningococcal disease until proven otherwise. This finding indicates **meningococcemia** (bacteremia with endothelial invasion) and carries risk of **septic shock**. ## Immediate Management Priorities ### 1. Antibiotic Therapy - **Ceftriaxone 80 mg/kg/day IV** (divided 6-hourly; max 2 g per dose) — excellent CSF penetration, covers meningococci and pneumococci. - **Vancomycin 15–20 mg/kg IV 8–12-hourly** — added empirically for PRSP coverage until culture results available. - **Dexamethasone 0.15 mg/kg IV 6-hourly for 4 days** — reduces mortality and hearing loss in meningococcal meningitis. ### 2. Hemodynamic Support (CRITICAL) **Warning:** This child is in **early septic shock** (low BP, prolonged capillary refill time, tachycardia). Meningococcal sepsis has high mortality if shock is not rapidly reversed. - **Aggressive IV fluid resuscitation**: 20 mL/kg bolus of 0.9% saline or Ringer's lactate over 15–30 minutes; repeat if hypotension persists. - **Vasopressors** (e.g., noradrenaline) if fluid-refractory hypotension develops. - **ICU admission** for continuous monitoring and support. ### 3. Infection Control - **Respiratory isolation** for first 24 hours of antibiotics. - **Chemoprophylaxis for close contacts**: Rifampicin or ceftriaxone (see local guidelines). **High-Yield:** Meningococcal meningitis is a medical emergency. Mortality in untreated or delayed-treatment septic shock exceeds 50%. Early recognition of the rash and aggressive resuscitation are life-saving. **Mnemonic: RASH** — **R**ash (non-blanching) + **A**ntibiotics (ceftriaxone + vancomycin) + **S**eptic shock (fluid resuscitation) + **H**ospital ICU admission.