Cough Does Not Reduce the Likelihood of Meningitis
The presence of a cough does not reliably reduce the likelihood of meningitis, as clinical characteristics alone cannot be used to rule out bacterial meningitis. 1
Clinical Presentation of Meningitis
Bacterial meningitis presents with a wide range of symptoms, and no single clinical sign is present in all patients:
In adults, common presentations include:
In children beyond neonatal age:
- Fever (92-93%)
- Vomiting (58-67%)
- Headache (78%)
- Neck stiffness (40-82%) 2
The classic triad of fever, neck stiffness, and altered mental status is present in only 41-51% of patients with bacterial meningitis 1
Respiratory Symptoms and Meningitis
While cough is often associated with respiratory infections, its presence does not exclude meningitis:
The European Society of Clinical Microbiology and Infectious Diseases guidelines explicitly state that "clinical characteristics cannot be used to rule out bacterial meningitis" 1
No published diagnostic algorithm for meningitis has 100% sensitivity, meaning that relying on the absence or presence of specific symptoms (including cough) will miss cases of bacterial meningitis 1
In pediatric patients, the American College of Emergency Physicians guidelines recommend obtaining a chest radiograph for febrile children with cough and other symptoms, but this is to evaluate for pneumonia, not to exclude meningitis 1
Diagnostic Approach
Given the limitations of clinical assessment alone:
Cerebrospinal fluid examination is essential for definitive diagnosis of suspected bacterial meningitis, unless contraindications for lumbar puncture are present 1, 2
Do not rely on the absence of classic signs to exclude the diagnosis of meningitis 2
Consider lumbar puncture in patients with concerning symptoms even if they have respiratory symptoms like cough 1
Common Pitfalls to Avoid
Relying solely on classic symptoms: The absence of classic meningeal signs does not rule out meningitis 1, 2
Assuming alternative diagnoses: Patients with respiratory symptoms may have concurrent meningitis 3
Delaying diagnosis: Early diagnosis and appropriate antibiotic treatment are critical for reducing mortality and neurological sequelae 4
Overlooking subtle presentations: In patients without meningeal irritation signs, headache, nausea, vomiting, painful eye movements, and phonophobia may increase the likelihood of meningitis 3
In summary, while respiratory symptoms like cough may suggest alternative diagnoses, their presence should not lower clinical suspicion for meningitis when other concerning features are present. The definitive diagnosis of meningitis requires cerebrospinal fluid examination.