Snapshot A 19-year-old man presents to the emergency department with a headache. His headache was initially mild but then subsequently worsened over the course 2 days. His headaches are associated with fevers, chills, photophobia, and neck stiffness. His temperature is 101°F (38.3°C), blood pressure is 124/95 mmHg, pulse is 118/min, and respirations are 22/min. Physical examination is notable for nuchal rigidity and petechieal hemorrhages in the skin. An emergent lumbar puncture is performed and blood cultures are obtained. Immediately after, he is started on intravenous vancomycin and ceftriaxone. (Meningococcal meningitis) Introduction Definition login to view 5 more bullets Etiology login to view 15 more bullets Epidemiology login to view 3 more bullets Prognosis login to view 1 more bullet Presentation Symptoms login to view 3 more bullets Physical exam login to view 9 more bullets Studies Lumbar puncture login to view 10 more bullets Serum studies login to view 2 more bullets Cerebrospinal Fluid Analysis Test Normal Bacterial Viral Fungal/TB Opening pressure ≤ 20 cm H 2O ↑ Normal or slightly ↑ ↑ Color Clear Cloudy Clear Cloudy Cell count 0-5 cells/µL ↑ PMN ↑ (Lymphocytes) ↑ (Lymphocytes) Protein < 45 mg/dL ↑ Slighty ↑ ↑ CSF:Serum glucose > 0.6 ↓ Normal ↓ Treatment Bacterial Population Causative Organism Treatment Infants (<1 month) Streptococcus agalactiae (group B streptococcus) Listeria monocytogenes Escherichia coli other gram-negative bacilli Ampicillin and cefotaxime 1-23 months of age Streptococcus pneumoniae Neisseria meningitidis S. agalactiae Haemophilus influenzae E. coli Vancomycin and ceftriaxone In cases of streptococcal pneumoniae, patients can benefit from dexamethasone 2-50 years of age N. meningitidis S. pneumoniae Vancomycin and ceftriaxone > 50 years of age of immunocompromised S. pneumoniae Listeria monocytogenes N. meningitidis aerobic gram-negative bacilli Vancomycin, ceftriaxone, and ampicillin Viral meningitis login to view 1 more bullet Meningococcal prophylaxis login to view 10 more bullets Cryptococcal meningitis login to view 2 more bullets Complications Neurological sequela (e.g., cognitive deficit) Septic sinus thrombosis Subudural effusion or empyema