What are the differential diagnoses and initial management for an adult presenting with retro‑orbital headache?

Retro-orbital Headache: Differential Diagnosis and Initial Management

For an adult presenting with retro-orbital headache, immediately assess for red flags (thunderclap onset, focal neurological deficits, visual changes, fever, or age >50 with new headache) and perform a focused neurological examination including fundoscopy and cranial nerve testing, as any abnormality mandates emergent neuroimaging. 1

Immediate Red Flag Assessment

Perform these critical examinations first:

• Fundoscopic examination to check for papilledema indicating increased intracranial pressure 1
• Complete cranial nerve examination - any abnormality requires neuroimaging 1
• Assess for proptosis, visual changes, or abnormal extraocular movements suggesting orbital or intracranial complications 1
• Check vital signs including temperature, as fever with retro-orbital pain raises concern for infection or vasculitis 2

If any red flags are present, obtain emergent MRI (preferred over CT) and consider immediate specialist consultation. 1, 3

Primary Differential Diagnoses for Retro-orbital Pain

Cluster Headache (Most Characteristic for Retro-orbital Location)

Cluster headache presents with severe unilateral periorbital/supraorbital pain lasting 15-180 minutes, occurring 1-8 times daily, and MUST have ipsilateral autonomic features: lacrimation, nasal congestion, rhinorrhea, ptosis, miosis, or eyelid edema. 1, 4

Key distinguishing features:

• Patients are restless and agitated during attacks (unlike migraine where patients prefer to lie still) 4, 5
• Attacks occur in clusters with circadian and circannual periodicity, often at precise times, especially at night 5, 6
• Alcohol triggers attacks during cluster periods 5
• Affects predominantly males, prevalence ~0.1% 3

Migraine Without Aura

Migraine requires at least 2 of: unilateral location, pulsating quality, moderate-to-severe intensity, aggravation by routine activity; AND at least 1 of: nausea/vomiting OR photophobia and phonophobia. 1, 4

Key distinguishing features:

• Duration 4-72 hours (much longer than cluster headache's 15-180 minutes) 4
• Patients prefer to lie still in a dark, quiet room (opposite of cluster headache restlessness) 4
• Affects 18% of women and 6.5% of men 3

Acute Bacterial Rhinosinusitis (ABRS)

Diagnose ABRS when purulent nasal discharge, nasal obstruction, and facial pressure-fullness persist ≥10 days OR worsen within 10 days after initial improvement ("double worsening"). 1, 2

Key features:

• Facial pain-pressure-fullness may involve periorbital region or manifest as headache 2
• Check for purulent nasal discharge (cloudy or colored) on examination 2, 1
• Palpate for sinus tenderness and check for mucosal erythema 1
• Imaging is NOT indicated for uncomplicated sinusitis - diagnosis is clinical 1

Giant Cell Arteritis (GCA) - Critical to Exclude in Age >50

In patients over age 50, immediately assess for GCA symptoms: temporal tenderness, jaw claudication, weight loss, proximal myalgia, fever, or history of polymyalgia rheumatica. 2

Critical actions:

• Obtain immediate ESR, CRP, and CBC with platelets if GCA suspected 2
• GCA typically presents with optic disc swelling, retinal artery occlusion, and absence of emboli 2
• Prompt initiation of systemic corticosteroids is critical to prevent vision loss in the fellow eye 2

Retinal/Ophthalmic Artery Occlusion

Orbital involvement from vascular occlusion can present with retro-orbital pain, exophthalmos, oculomotor nerve palsy, or vision loss. 2

• Acute symptomatic retinal artery occlusion represents an urgent ophthalmic emergency requiring prompt evaluation 2
• Refer immediately to stroke center as risk of ischemic stroke is 3-6% in first 1-4 weeks, with 20-24% having concurrent stroke 2

Initial Management Algorithm

If Red Flags Present:

• Emergent MRI and immediate specialist consultation 1
• If GCA suspected: start corticosteroids immediately while awaiting test results 2

If Symptoms Suggest Viral Rhinosinusitis (<10 days, not worsening):

• Symptomatic treatment only: acetaminophen or NSAIDs for pain 1
• Nasal saline irrigation 1
• Short-term pseudoephedrine ≤3-5 days to avoid rebound congestion 1

If ABRS Diagnosed (≥10 days OR worsening pattern):

• First-line: Amoxicillin-clavulanate for 7-10 days 1
• Reassess immediately if: high fever develops, severe facial pain worsens, neurological symptoms appear, or symptoms persist beyond 10-14 days 1

If Cluster Headache Diagnosed:

Acute treatment:

• First-line: Subcutaneous sumatriptan 6 mg (70% relief within 10 minutes) 4
• Alternative first-line: 100% oxygen inhalation at 12 L/min (equal efficacy to sumatriptan) 4
• Screen for CAD risk factors before prescribing sumatriptan (hypertension, hypercholesterolemia, smoking, obesity, diabetes, family history) 4
• Alternative: Intranasal zolmitriptan 10 mg 4

Prophylactic treatment:

• First-line: Verapamil 360 mg/day with ECG monitoring for PR interval prolongation 4
• Bridging therapy: Oral corticosteroids or greater occipital nerve blockade while verapamil takes effect 4

If Migraine Diagnosed:

Acute treatment:

• Triptan combined with NSAID or acetaminophen, plus antiemetic 1
• Limit acute medication use to ≤10 days/month to prevent medication overuse headache 1

Common Pitfalls to Avoid

• Do not dismiss retro-orbital pain in patients >50 without evaluating for GCA - this is an ophthalmologic emergency 2
• Do not obtain nasal cavity or nasopharyngeal cultures for routine ABRS - they correlate poorly with sinus cultures 2
• Do not prescribe triptans without cardiovascular screening in cluster headache patients 4
• Do not assume isolated facial pain without purulent nasal discharge is sinusitis - the differential is broad and specificity increases only with concurrent purulent discharge 2
• Do not delay stroke workup in acute retinal artery occlusion - 19-25% have silent brain infarction on MRI 2