1. Viral Meningitis Myra Lalas Pitt

2. Definition  Meningeal inflammation with negative cultures for routine bacterial pathogens in a patient who did not receive antibiotics before lumbar puncture.  Most commonly due to enterovirus.  Mainly affects infants < 1 year and children 5 to 10 years of age.  Peak incidence occurs from late spring to autumn, reflecting the peak activity of enteroviral and arthropod- borne infections

4. Signs and Symptoms  Fever  Headache  Sore throat  Cough  Runny nose  Vomiting  Photophobia  Neck pain  Bulging fontanelle  Seizures  Lethargy

5. Differentials  Severe pharyngitis  Pharyngeal abscess  Musculoskeletal strain  Upper lobe pneumonia  Cervical spine osteomyelitis  Epidural abscess  Subarachnoid hemorrhage  Encephalitis  Ingestions  Mass lesions of the CNS  Simple febrile seizure.  Sinusitis  Mastoiditis  Brain abscess

6. Diagnosis

7. CSF Interpretation  WBC ranges from 10 to 500 cells/microL (higher values can be seen with some viruses). Normal CSF WBC counts can be seen in EV meningitis (particularly in young infants).  CSF WBC usually has lymphocytic predominance.  Glucose: Normal or slightly reduced, but usually ≥40 percent of the serum value  Protein: Normal to slightly elevated, but usually less than 150 mg/dL

8. Treatment  Rest in a quiet, dimly lit room.  Acetaminophen or NSAIDS for headache, pain, and fever; Aspirin should be avoided because of its association with Reye syndrome  IVF if patient has poor PO.  Empiric antimicrobial therapy should be provided to patients in whom bacterial meningitis is suspected or cannot be excluded while awaiting the results of cultures.

9. References  Harper Marvin B, "Chapter 16. Meningitis" (Chapter). Samir S. Shah: Pediatric Practice: Infectious Disease: http://www.accesspediatrics.com/content/6903048.  Modlin John F, "Chapter 232. Viral Infections of the Central Nervous System" (Chapter). Colin D. Rudolph, Abraham M. Rudolph, George E. Lister, Lewis R. First, Anne A. Gershon: Rudolph's Pediatrics, 22e: http://www.accesspediatrics.com/content/7022413.  www.uptodate.com