What are the symptoms of meningitis?

Symptoms of Meningitis

The most common symptoms of meningitis include fever, headache, neck stiffness, and altered mental status, though no single symptom is present in all patients and presentation varies by age group. 1

Age-Specific Presentation

Neonates

• Present with nonspecific symptoms:
  • Irritability
  • Poor feeding
  • Respiratory distress (present in 72% of GBS meningitis cases)
  • Pale or marble skin
  • Hyper- or hypotonia
  • Fever (present in only 6-39% of cases)
  • Seizures (9-34% of cases)
  • Cardiovascular symptoms (69% in GBS meningitis)
  • Neurological symptoms (63% in GBS meningitis)
  • Concomitant septic shock (25% of cases) 1

Children Beyond Neonatal Age

• Fever (92-93% of cases) - most common symptom
• Headache (75% in children >5 years, only 2-9% in children <1 year)
• Neck stiffness (40-82%)
• Vomiting (55-67%)
• Altered mental status (13-56%)
• Seizures (10-56%)
• Photophobia
• Chills
• Rash (4-51%, more common with meningococcal infection) 1

Adults

• Headache (58-87%)
• Fever >38.0°C (77-97%)
• Neck stiffness (65-83%)
• Altered mental status (30-69%)
• Nausea/vomiting (45-74%)
• Photophobia
• Rash (20-52%, indicative of meningococcal infection in >90% of cases)
• Focal neurologic deficits (15-34%)
• Coma (7-16%) 1

Classic Triad and Diagnostic Challenges

The classic triad of fever, neck stiffness, and altered mental status is present in only 41-51% of adult cases 1, 2. This underscores the importance of maintaining a high index of suspicion even when the full triad is absent.

Diagnostic Accuracy of Clinical Signs

• Neck stiffness: sensitivity 31% in adults, 51% in children
• Kernig sign: sensitivity 11% in adults, 53% in children
• Brudzinski sign: sensitivity 9% in adults, 66% in children 1

These low sensitivities mean that the absence of these classic signs cannot rule out meningitis.

Important Clinical Pitfalls

1. Age-dependent presentation: Younger patients, especially infants, present with more subtle and atypical symptoms 1

2. Absence of classic signs: No single clinical sign is present in all patients with bacterial meningitis 1

3. Rapid progression: Bacterial meningitis can progress rapidly with potentially fatal outcomes if treatment is delayed 2

4. Pathogen-specific symptoms: Some symptoms correlate with specific pathogens:

   • Petechial/purpuric rash: Strongly associated with meningococcal disease (present in 61% of confirmed cases) 1

5. Post-discharge sequelae: Even after successful treatment, patients may experience fatigue, headaches, sleep disorders, and emotional problems for weeks or months 2

Clinical Algorithm for Suspecting Meningitis

1. High-risk presentation (requires immediate action):

   • Fever + any neurological sign
   • Severe headache of abrupt onset or "worst headache of life"
   • Headache + photophobia
   • Rash (especially petechial) + any meningeal sign

2. Consider meningitis when these laboratory findings are present:

   • Serum leukocytes >10.0 ×10⁹/L
   • CSF leukocytes >2000/μL
   • CSF granulocytes >1180/μL
   • CSF protein >2.2 g/L
   • CSF glucose <34.23 mg/dL 3

3. Proceed to lumbar puncture unless contraindications exist (such as focal neurological deficits, papilledema, altered mental status, or history of immunocompromising conditions) 3

Remember that clinical characteristics alone cannot rule out bacterial meningitis, and a low threshold for performing diagnostic procedures should be maintained, especially in neonates and young children 1.