Giant Cell Arteritis: Always Keep It In Your Head - BPJ 53 - Bpac NZ

Giant cell arteritis is an immune-mediated, ischaemic condition caused by inflammation in the wall of medium to large arteries. While it can affect all medium to large arteries in the head, neck and upper torso, the involvement of the temporal artery is usually the only artery in which physical changes are clinically apparent (giving rise to the alternative name of temporal arteritis). It is the most common form of vasculitis in adults.1

Giant cell arteritis usually affects people aged over 50 years,2 and is only rarely seen in younger people. It is most prevalent in Caucasians, particularly of Northern-European (e.g. Scandinavian) descent, and is two to three times more common in females than males.3 Worldwide, incidence ranges between 10 – 20 cases per 100 000 people aged over 50 years.3 A New Zealand study found a similar local incidence of 12 cases per year, per 100 000 people aged over 50 years.4

Symptoms of giant cell arteritis include headache, scalp tenderness, jaw claudication or other orofacial pain, neck or shoulder pain, visual disturbances and systemic symptoms, such as sweats, fever and anorexia. There may be palpable changes to the temporal artery on examination. An acute phase response is usually seen on laboratory assessment, and a temporal artery biopsy will show inflammation and multinucleated cells with involvement of the internal elastic lamina.

If undetected, giant cell arteritis can result in catastrophic sequelae, such as irreversible visual loss, stroke and aortic aneurysm. Visual loss, due to ischaemic optic neuropathy, is an early manifestation and can be a presenting symptom. This occurs in 20 – 50% of people with giant cell arteritis if they are untreated.5, 6 Large-vessel stenosis, and with it an increased risk of stroke, occurs in 10 – 15% of people.7, 8 Prompt treatment with corticosteroids can markedly reduce these risks. For example, the likelihood of visual loss decreases from 20% to 1% in patients with no preceding visual loss once treatment is initiated.7 Patients who already have some visual loss at the initial presentation, however, have a poorer prognosis. One-quarter of patients develop further visual deterioration in the same eye, and up to 10% lose vision in the other eye, usually within the first few days, despite treatment.9

Giant cell arteritis should be strongly considered in older patients presenting with a new type of headache, jaw pain or visual disturbances (also see: "Making a diagnosis"). Whenever there is a reasonable suspicion of the condition, discuss the patient with an Ophthalmologist or Rheumatologist (depending on local guidelines/protocols) to organise referral for a temporal artery biopsy, and initiate same-day treatment with corticosteroids. Where there is a strong clinical suspicion of giant cell arteritis, a delay in treatment will almost always have greater consequences than an unnecessary dose of corticosteroids in someone who is later found to not to have the condition.