Giant cell arteritis (temporal arteritis)

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How the diagnosis is reached

New-onset headache over 50 with scalp tenderness and a markedly raised ESR is giant cell arteritis until disproven, and the jaw claudication settles it: pain that comes on with chewing and resolves with rest is the single most specific symptom, reflecting ischemia of the masseter through branches of the external carotid. The pulseless temporal artery on one side with a normal vessel opposite is the characteristic finding, and the girdle stiffness is the polymyalgia rheumatica that coexists in roughly half of cases; a normal creatine kinase distinguishes this from an inflammatory myopathy, and the raised alkaline phosphatase is the mild cholestatic picture of active disease, not liver or bone pathology. The episode of transient monocular visual loss is amaurosis fugax from involvement of the posterior ciliary arteries, and untreated it heralds permanent, painless and irreversible blindness, which can arrive within days and may then take the second eye. Ultrasound showing a non-compressible halo supports the diagnosis, and the thickened right axillary artery marks this as a large-vessel vasculitis reaching well beyond the temple. Biopsy is confirmatory, but the critical management principle is that high-dose glucocorticoids must be started the moment the diagnosis is suspected, without waiting for either. Because she has already had amaurosis fugax, that means intravenous methylprednisolone rather than the oral prednisolone which would serve for headache alone. Biopsy stays informative for about two weeks after steroids begin, and the skip lesions here explain why specimen length matters and why a negative biopsy does not exclude the disease. Tocilizumab is added as a steroid-sparing agent given the long treatment course and the burden of steroid toxicity in this age group, with bone and gastric protection alongside it for the same reason.

Key clinical clues

• New headache over age 50 with scalp tenderness in a new distribution
• Jaw claudication, pain on chewing that resolves with rest, the most specific symptom
• Thickened, tender, pulseless temporal artery with a normal contralateral vessel
• ESR 96 with thrombocytosis and normocytic anemia; normal CK despite girdle stiffness
• Transient monocular visual loss, do not wait for biopsy before starting steroids

The case in full

1

Presenting complaint

Patient history

A 73-year-old woman has three weeks of a new right-sided headache over her temple, different from her usual headaches. Brushing her hair on that side hurts. Her jaw aches after a few minutes of chewing and settles when she stops, so she avoids meat.

2

Examination and observations

Physical examination

The right temporal artery is thickened, tender and pulseless; the left pulsates normally. She has marked stiffness and aching in both shoulders and hips, worst in the hour after waking, but no true weakness. Fundoscopy and acuity are normal, with no scalp rash.

Measurements

Parameter	Value	Reference
Temperature	37.6 °CRef 36.1–37.5	36.1–37.5
Blood pressure	142/78 mmHg	–
Heart rate	84 bpmRef 60–100	60–100

3

Inflammatory markers and blood count

Laboratory results

A blood count and inflammatory markers are sent.

Measurements

Parameter	Value	Reference
ESR	96 mm/hRef <30	<30
C-reactive protein	84 mg/LRef <5	<5
Platelets	612 ×10⁹/LRef 150–400	150–400
Hemoglobin	10.4 g/dLRef 12.0–15.5	12.0–15.5
Mean cell volume	87 fLRef 80–100	80–100
Alkaline phosphatase	184 U/LRef 44–147	44–147
Creatine kinase	82 U/LRef 30–200	30–200

4

Clinical course

Clinical course

While awaiting outpatient review two days later, she has a sudden episode in which the vision in her right eye greys out completely, as though a curtain had descended. It returns fully after about five minutes. She has had no weakness, speech disturbance or facial droop.

5

Vascular ultrasound

Imaging

Colour Doppler of both temporal arteries shows hypoechoic, concentric, non-compressible wall thickening around the lumen of the right superficial temporal artery over roughly 2 cm. The left shows a shorter similar segment, and the right axillary artery is also thickened.

6

Histopathology

Pathology

A 2 cm biopsy specimen is taken; a high-power H&E section through the vessel wall is shown below. The changes are patchy along the specimen, with several histologically normal segments between the affected areas.