Pyogenic (Bacterial) Meningitis
A medical emergency requiring immediate recognition and initiation of antibiotics to prevent irreversible neurological damage.
1. Etiology (Age-Specific)
| Age Group | Most Common Pathogens |
|---|---|
| Neonates | Group B Streptococcus, E. coli, Listeria monocytogenes. |
| Infants/Children | Streptococcus pneumoniae, Neisseria meningitidis. |
2. Clinical Features
- Classic Triad: Fever, neck stiffness (nuchal rigidity), and altered mental status.
- Signs of Meningeal Irritation: Kernig’s sign and Brudzinski’s sign.
- Infant Presentation: Often non-specific—poor feeding, lethargy, bulging fontanelle, and seizures.
3. Management Pearls
- CSF Analysis: Increased neutrophils, high protein, and low glucose.
- Empiric Therapy: IV Ceftriaxone + Vancomycin (add Ampicillin for neonates or suspected Listeria).
- Adjunct: Dexamethasone to reduce neurological sequelae (especially in H. influenzae).
NEET PG Hint: Remember that Lumbar Puncture (LP) is the definitive diagnostic step. If signs of raised intracranial pressure (ICP) are present, perform a CT scan before the LP to avoid the risk of brain herniation.