How should I evaluate and manage a patient with a two‑day history of fever and headache without other symptoms?

Evaluation of Fever and Headache for 2 Days Without Other Symptoms

Immediately assess for red flags that indicate serious secondary causes requiring urgent investigation, particularly meningitis, which can present with just fever and headache before other symptoms develop. 1

Critical Red Flag Assessment

Screen for the following red flags that mandate immediate further workup:

• Altered mental status or confusion – even subtle changes warrant concern for meningitis or encephalitis 1, 2
• Neck stiffness – though absence does NOT rule out meningitis, especially in early presentation 1
• Fever with unexplained severity or pattern – particularly if associated with rigors 1
• Thunderclap or sudden-onset severe headache – suggests subarachnoid hemorrhage 3, 2
• Headache that is progressively worsening over 2 days – concerning for evolving pathology 2
• New headache in patient >50 years old – lower threshold for serious pathology 3, 4
• Focal neurological symptoms – any weakness, sensory changes, or visual disturbances 1
• Seizures – document presence or absence 1
• Any rash – specifically look for petechial or purpuric rash suggesting meningococcemia 1

Critical pitfall: Do not rely on Kernig's or Brudzinski's signs – these have poor sensitivity and their absence does not exclude meningitis. 1 The elderly are particularly likely to present atypically with altered consciousness but without fever or neck stiffness. 1

Immediate Management if Red Flags Present

If ANY red flags are present, refer immediately to hospital via emergency ambulance for arrival within 1 hour. 1

Hospital evaluation should include:

• Lumbar puncture – mandatory when meningitis suspected, unless contraindicated by focal neurological signs or concern for elevated intracranial pressure 1
• Neuroimaging before LP – obtain non-contrast head CT first if focal neurological deficits, altered consciousness, or concern for mass effect 3, 4
• Blood cultures, complete blood count, inflammatory markers (CRP, lactate dehydrogenase) 1
• Empiric antibiotics – should be administered immediately if bacterial meningitis suspected, even before LP if there will be delay 1

Evaluation if No Red Flags Present

If the patient has isolated fever and headache without any red flags, consider common primary headache disorders and viral syndromes:

Key Historical Features to Elicit

• Headache characteristics: unilateral vs bilateral, pulsating vs pressing quality, intensity, aggravation with routine activity 1, 2
• Associated symptoms: nausea/vomiting, photophobia, phonophobia – presence suggests migraine 2
• Duration of individual headache episodes: migraine typically 4-72 hours if untreated 3
• Family history of migraine – strengthens migraine diagnosis 3
• Recent viral prodrome symptoms: myalgias, malaise, upper respiratory symptoms 1
• Medication use: assess for medication overuse (analgesics ≥15 days/month or triptans ≥10 days/month) 4, 2

Physical Examination

• Vital signs: document fever pattern and hemodynamic stability 1
• Complete neurological examination: mental status, cranial nerves, motor/sensory function, reflexes, gait 1, 2
• Meningeal signs: neck stiffness (though unreliable as noted above) 1
• Skin examination: thoroughly inspect for any rash 1
• Fundoscopic examination: assess for papilledema if concern for elevated intracranial pressure 2

Differential Diagnosis Without Red Flags

Viral syndrome with headache – most common cause of acute fever with headache in otherwise healthy adults:

• Typically self-limited over 2-7 days 1
• May have mild myalgias or malaise 1

Migraine triggered by viral illness:

• Unilateral, pulsating, moderate-severe intensity 2
• Aggravated by routine activity 2
• Accompanied by nausea/vomiting OR photophobia and phonophobia 2

Tension-type headache with concurrent febrile illness:

• Bilateral, pressing/tightening quality 1, 2
• Mild-moderate intensity, not aggravated by activity 1, 2

Management Approach Without Red Flags

For presumed viral syndrome with headache:

• Symptomatic treatment with NSAIDs (naproxen 500 mg) or acetaminophen 2
• Adequate hydration and rest
• Safety-net advice: Return immediately if develops altered mental status, neck stiffness, rash, worsening headache, or any new neurological symptoms 1

For migraine:

• Acute treatment: triptans (sumatriptan 50-100 mg) for moderate-severe attacks, or NSAIDs for mild-moderate 4, 2
• Address fever as potential trigger

When to Image

Neuroimaging is NOT indicated for typical primary headache without red flags. 1, 3

Obtain MRI with and without contrast (preferred) or non-contrast CT if:

• Any red flags present as listed above 3, 4
• Patient age >50 with new-onset headache, even without classic red flags 4
• Diagnostic uncertainty after thorough evaluation 3

If CT/MRI normal but subarachnoid hemorrhage still suspected clinically, perform lumbar puncture for CSF analysis. 4

Follow-up and Referral

Arrange urgent follow-up within 24-48 hours if:

• Symptoms not improving or worsening 1
• New symptoms develop
• Diagnostic uncertainty remains 2

Refer to neurology if:

• Headache pattern changes or becomes chronic 2
• Diagnosis remains uncertain after initial evaluation 3, 2
• Poor response to initial management 4, 2

The key principle: fever with headache requires high vigilance for meningitis, which can be rapidly fatal if missed. When in doubt, refer for urgent evaluation and lumbar puncture. 1