How can I differentiate between giant cell arteritis and other causes of headache in older adults?

Differentiating Giant Cell Arteritis (GCA) from other causes of headache in older adults involves recognizing specific symptoms and the urgency associated with GCA ¹. GCA is a medical emergency due to the risk of sudden irreversible sight loss and other serious complications ¹.

• Giant Cell Arteritis (GCA):
• Typically affects individuals from age 40 years onwards ¹.
• Headache is a common symptom ².
• Key differentiating features include new visual loss (transient or permanent), double vision, jaw claudication, and scalp tenderness ¹,².
• Blood tests may show elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), although these can be normal in some cases ¹. Normochromic normocytic anaemia and elevated platelet count are also common ¹.
• If GCA is strongly suspected, immediate treatment with high-dose glucocorticoids and urgent referral to a specialist (rheumatologist) via a fast-track pathway is crucial, ideally on the same working day and within 3 working days ¹. If there is new visual loss or double vision, arrange an urgent (same day) assessment by an ophthalmologist ¹. Do not delay referral while waiting for blood test results if GCA is strongly suspected ¹.
• Other Headache Causes and Differentiating Features:
• Tension-type headache: Often bilateral, described as pressing/tightening (non-pulsating), mild or moderate intensity, and not aggravated by routine activities ².
• Migraine (with or without aura): Can be unilateral or bilateral, pulsating (throbbing), moderate or severe intensity, aggravated by routine activities, and may be accompanied by sensitivity to light and/or sound, nausea, and/or vomiting ². Aura symptoms are fully reversible, develop gradually over at least 5 minutes, and last 5 to 60 minutes, including visual disturbances, sensory symptoms, or speech disturbance ².
• Cluster headache: Unilateral pain, typically around or above the eye and along the side of the head/face ². Pain is severe or very severe and can be sharp, boring, burning, throbbing, or tightening ². Associated symptoms on the same side as the headache include red and/or watery eye, nasal congestion and/or runny nose, swollen eyelid, forehead and facial sweating, and constricted pupil and/or drooping eyelid ². Restlessness or agitation is common ².
• Subarachnoid Haemorrhage (SAH): Characterized by a 'thunderclap' headache, which is a sudden severe headache typically peaking in intensity within 1 to 5 minutes ³. Other symptoms may include neck pain or stiffness, photophobia, nausea and vomiting, new symptoms of altered brain function (e.g., reduced consciousness, seizure, focal neurological deficit), or limited/painful neck flexion ³. Urgent investigation is required ³.
• Acute Narrow-Angle Glaucoma: May present with headache along with a painful red eye, misty vision or haloes, and sometimes nausea ². A semi-dilated pupil may be present ².
• Medication Overuse Headache: Occurs due to the overuse of acute headache medications and is treated by withdrawing the overused medication ².
• General Red Flags for Headache in Older Adults (requiring further investigation/referral):
• Worsening headache with fever ².
• Sudden-onset headache reaching maximum intensity within 5 minutes ².
• New-onset neurological deficit or cognitive dysfunction ².
• Change in personality or impaired level of consciousness ².
• Recent (within 3 months) head trauma ².
• Headache triggered by cough, Valsalva manoeuvre, sneeze, or exercise ².
• Orthostatic headache (changes with posture) ².
• Compromised immunity (e.g., HIV, immunosuppressive drugs) ².
• History of malignancy known to metastasise to the brain ².
• Vomiting without other obvious cause ².
• A substantial change in the characteristics of their headache ².