What could be causing daily headaches and tenderness on the left side of my scalp?

Daily Headaches with Left-Sided Scalp Tenderness

You must be evaluated urgently to exclude giant cell arteritis (GCA), especially if you are over age 50, as this condition can cause permanent blindness within days if untreated. 1, 2

Immediate Evaluation Required

Red Flag Assessment

• Age over 50 with new-onset headache: This is a critical red flag requiring urgent evaluation for GCA, which presents with scalp tenderness and daily headaches 1, 3, 4
• Jaw claudication: Ask yourself if you experience pain in your jaw when chewing—this is pathognomonic for GCA and demands immediate medical attention 1, 2
• Visual symptoms: Any vision changes, even transient, indicate potential ischemic optic neuropathy requiring emergency treatment 1
• Temporal artery abnormalities: Palpate your temples for tenderness, thickening, or decreased pulse—these findings have 90.6% specificity for GCA 1

When to Seek Emergency Care

You need emergency evaluation if you have any of the following 3, 4:

• Age over 50 with new headache pattern
• Sudden onset "thunderclap" headache
• Headache awakening you from sleep
• Progressive worsening over days to weeks
• Any neurological symptoms (weakness, vision changes, confusion)
• Fever with headache

Most Likely Diagnoses Based on Your Symptoms

Giant Cell Arteritis (If Age >50)

• Scalp tenderness is a hallmark feature of GCA, particularly when localized to one side 1, 2
• Daily headaches in an elderly patient with scalp tenderness should never be attributed to migraine without excluding GCA first 1
• Treatment cannot wait: If GCA is suspected, corticosteroids must be started immediately before any diagnostic testing to prevent irreversible blindness 1
• ESR and CRP should be drawn, but treatment should not be delayed for results—approximately 11% of GCA patients have normal inflammatory markers 1

Chronic Migraine (If Age <50)

• Chronic migraine is defined as ≥15 headache days per month for >3 months with migraine features on ≥8 days 5
• Unilateral location and scalp tenderness can occur with migraine, particularly when associated with cutaneous allodynia 5
• Daily headaches may indicate transformation from episodic to chronic migraine, often triggered by medication overuse 5

Medication-Overuse Headache

• Suspect this if you take any pain medication ≥10 days per month for >3 months 5, 6
• This includes over-the-counter analgesics, triptans, opioids, or combination products containing caffeine or butalbital 5
• Medication overuse causes a pattern of increasing headache frequency, often resulting in daily headaches 5
• Common pitfall: Patients often don't report over-the-counter medication use unless specifically asked 6

Tension-Type Headache

• Bilateral pressing or tightening pain is typical, though unilateral presentation can occur 5, 7
• Scalp tenderness on palpation is common in tension-type headache due to pericranial muscle tenderness 7
• No nausea/vomiting and no aggravation with routine activity distinguish this from migraine 5

Diagnostic Approach

History Details to Document

• Age at onset of current headache pattern 5
• Duration and frequency: How many days per month do you have headache? 5
• Pain characteristics: Throbbing vs. pressing, severity (0-10 scale), what makes it worse or better 5
• Associated symptoms: Nausea, vomiting, light sensitivity, sound sensitivity 5
• Medication use: Document ALL pain medications including over-the-counter drugs, frequency of use 5, 6
• Temporal artery symptoms: Jaw pain with chewing, vision changes, scalp pain when combing hair 1, 2

Physical Examination Priorities

• Palpate temporal arteries bilaterally for tenderness, thickening, or absent pulse 1
• Examine scalp for focal tenderness, particularly over temporal region 2
• Complete neurological examination to exclude focal deficits 5, 4
• Fundoscopic examination to assess for papilledema if increased intracranial pressure suspected 5

Laboratory Testing

• If age >50 or GCA suspected: Immediate ESR and CRP, but do not delay treatment for results 1
• Temporal artery biopsy can be performed up to 2 weeks after starting corticosteroids without affecting diagnostic yield 1

Neuroimaging Indications

Neuroimaging is NOT routinely needed for typical headache patterns, but is indicated for 5, 4:

• Rapidly increasing headache frequency
• Focal neurological signs or symptoms
• Headache awakening from sleep
• Abrupt onset of severe headache
• Marked change in headache pattern
• New headache after age 50 (after excluding GCA)

Management Strategy

If GCA is Suspected (Age >50 with Scalp Tenderness)

1. Start high-dose corticosteroids immediately before any testing 1
2. Draw ESR and CRP but do not wait for results 1
3. Arrange urgent ophthalmology or neurology consultation 1
4. Schedule temporal artery biopsy within days 1

If Chronic Migraine is Diagnosed

• Preventive therapy is mandatory for chronic migraine (≥15 headache days/month) 5
• Limit acute medication use to ≤2 days per week to prevent medication-overuse headache 5
• Consider referral to neurology for specialized treatments including CGRP monoclonal antibodies or onabotulinumtoxinA 3

If Medication-Overuse Headache is Present

• Withdraw the overused medication (opioids, barbiturates, benzodiazepines require slow taper; other agents can be stopped more quickly) 6
• Start preventive therapy for the underlying primary headache disorder 5, 6
• Expect temporary worsening of headache during withdrawal period 5

Critical Pitfalls to Avoid

• Never attribute new headache after age 50 to migraine without excluding GCA, especially with scalp tenderness 1, 3
• Never delay corticosteroids while awaiting diagnostic testing if GCA is suspected with any visual symptoms 1
• Do not pursue neuroimaging first when GCA is suspected based on classic symptoms—this wastes critical time 1
• Do not overlook medication overuse—specifically ask about all over-the-counter analgesics and frequency of use 5, 6
• Do not dismiss unilateral scalp tenderness as benign without thorough evaluation 2, 4