What's the next step for a 30-year-old female patient with a 5-day intractable migraine and a non-pruritic rash on her chest, with normal Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scan results?

Lumbar Puncture for Suspected Meningitis or Subarachnoid Hemorrhage

Given the 5-day duration of intractable migraine with a non-pruritic rash on the chest despite normal neuroimaging, the next critical step is to perform a lumbar puncture to rule out infectious or inflammatory causes, particularly meningitis or subarachnoid hemorrhage that may not be visible on imaging. 1

Rationale for Lumbar Puncture

• The combination of prolonged intractable headache with a rash raises concern for infectious etiologies, particularly meningitis, which can present with headache and rash even in the absence of classic meningeal signs 1
• Normal CT and MRI do not exclude subarachnoid hemorrhage (especially if imaging was performed more than 6 hours after onset), central nervous system infection, or inflammatory conditions 1
• The case report of a 44-year-old woman with headache who developed fever and altered mental status after initial migraine treatment demonstrates that serious secondary causes can initially masquerade as migraine 1

Red Flags Present in This Case

• Intractable nature (5 days): Typical migraine attacks last 4-72 hours; a 5-day continuous headache suggests status migrainosus or a secondary cause 2
• Non-pruritic rash: This is not a typical feature of primary migraine and raises concern for systemic infection, particularly meningococcemia or viral meningitis 1
• Poor response to treatment: True intractable migraine lasting 5 days despite presumed treatment attempts warrants investigation for secondary causes 2

Immediate Management Algorithm

Step 1: Perform Lumbar Puncture

• Obtain opening pressure, cell count with differential, glucose, protein, Gram stain, and bacterial culture 1
• Consider viral PCR panel (HSV, VZV, enterovirus) given the rash 1
• If opening pressure is elevated, this may indicate idiopathic intracranial hypertension, which can present with prolonged headache 1

Step 2: While Awaiting LP Results, Initiate Aggressive Migraine Treatment

• IV metoclopramide 10 mg plus IV ketorolac 30 mg as first-line combination therapy for severe intractable migraine 3
• Consider adding IV dihydroergotamine (DHE) if the above combination fails, as it has good evidence for status migrainosus 3, 4
• DHE dosing: 0.5-1 mg IV, can repeat every 8 hours (maximum 3 mg/24 hours, 4 mg/week) 4

Step 3: Initiate or Optimize Preventive Therapy

• Given the 5-day duration, this patient meets criteria for preventive therapy (headache lasting >3 days with disability) 2, 5
• First-line preventive options: Propranolol 80-160 mg daily, metoprolol 50-100 mg twice daily, or candesartan 16-32 mg daily 2
• Screen for contraindications: beta-blockers are contraindicated in asthma, cardiac failure, AV block, or depression 2

Critical Pitfall to Avoid

• Do not attribute all headaches with normal imaging to primary migraine: The presence of a rash is atypical for migraine and mandates investigation for secondary causes, particularly infectious etiologies 1
• Do not delay lumbar puncture: Even in the absence of fever or nuchal rigidity, meningitis can present with headache and rash, and delayed diagnosis can be catastrophic 1

If Lumbar Puncture is Normal

• Treat as status migrainosus (migraine attack lasting >72 hours) 6
• Continue IV therapy with metoclopramide + ketorolac, escalate to DHE if needed 3
• Strongly consider admission for IV therapy and monitoring if outpatient management has failed 6
• Limit acute medication use to prevent medication-overuse headache once the current episode resolves (no more than 2 days/week) 3, 2
• Mandatory initiation of preventive therapy given the severity and duration of this attack 2, 5, 6

Dermatology Consultation

• The non-pruritic rash warrants dermatologic evaluation to determine etiology, particularly to rule out viral exanthems, drug reactions, or systemic vasculitis that could be contributing to the headache 1