Viral Meningitis

Pt with h/o cold sores, genital herpes presents in August with H/A, neck stiffness, AMS x 48 hours. Reports irritability, lethargy, nausea, decreased appetite. Ill-appearing with fever, herpetic facial/genital lesion, multiple mosquito bites, positive Kernig/Brudzinski tests on exam.

• Pt < 19 y/o with bacterial meningitis score ≤ 2

• Obtain CBC, blood cx, CMP, TSH, RPR, B12, urine drug screen

• Obtain CSF

  • Immunosuppression, recent seizure, bradycardia, and/or AMS/neurologic deficit: Obtain head CT, start empiric antibiotics and dexamethasone prior to lumbar puncture

  • No contraindication to lumbar puncture: Perform procedure and start antibiotics, dexamethasone s/p CSF collection

• Treatment

  • See bacterial meningitis for prophylactic antibiotic and dexamethasone dosing

  • CSF with < 100 WBCs, < 50% neutrophils, protein < 20 g/L, normal glucose: Stop empiric antibiotics

  • CSF positive for > 1:700 WBC:RBC ratio and HSV on PCR: Start acyclovir 10 mg/kg q8h

  • Provide supportive care

Notes

• Etiology

  • Most commonly caused by enterovirus (51% of all US meningitis cases)

  • Most enterovirus cases occur between June and October with peak season in August

  • HSV accounts for 8% of all US meningitis cases

• Aseptic meningitis

  • Meningitis not caused by bacteria/fungi (i.e. culture negative)

  • Includes meningitis due to viruses, medications, etc.

• Time from symptom onset to hospital presentation averages 48 hours vs. 24 for bacterial meningitis

• Normal CSF glucose = serum glucose*0.67

Bacterial Meningitis

Pt with no h/o HiB/meningococcal/pneumococcal vaccination presents with H/A, neck stiffness, AMS x 24 hours. Reports irritability, lethargy, nausea, decreased appetite. Ill-appearing with fever, rash, and positive Kernig/Brudzinski tests on exam.

• Pt < 19 y/o with bacterial meningitis score ≥ 2

• Obtain CBC, blood cx, CMP, TSH, RPR, B12, urine drug screen

• CSF with WBCs > 500/hpf, neutrophils > 80%, protein > 50 g/L, glucose < 40 mg/dL, and PCR negative for HSV

  • Immunosuppression, recent seizure, bradycardia, and/or AMS/neurologic deficit: Obtain head CT, start empiric antibiotics and dexamethasone prior to lumbar puncture

  • No contraindication to lumbar puncture: Perform procedure and start antibiotics, dexamethasone s/p CSF collection

• Treatment

  • > 6 weeks old: Administer dexamethasone 0.5 mg/kg/day divided into four daily doses; discontinue if no H. influenza or S. pneumoniae on CSF culture

  • > 1 month old: Add CTX 1g q24h and vancomycin 15 mg/kg/dose q6h with trough goal 15-20

  • > 50 y/o: Add ampicillin 200 mg/kg/day divided every 4 hours to vancomycin/CTX for L. monocytogenes coverage

• Counseling

  • Family counseled that condition carries 15% mortality risk

  • Family advised that dexamethasone may reduce risk of hearing loss, mortality

  • Family counseled that close contact PPX will be necessary if H. influenzae, N. meningitidis, or S. pneumoniae present in CSF

  • F/u s/p discharge and administer HiB/meningococcal/pneumococcal vaccines

Notes

• Bacterial meningitis accounts for 14% of all US meningitis cases

  • N. meningitidis is more common in adolescents while S. pneumo is more common in adults

  • Healthy patients age 16-23 y/o should receive meningococcal vaccination

• Time from symptom onset to hospital presentation averages 24 hours vs. 48 for viral meningitis

• Normal CSF glucose = serum glucose*0.67

• Adjust antibiotic coverage and duration of therapy based on culture results