Author: Jade Nutting, Medical Student, University of Sydney, Sydney, NSW, Australia. DermNet NZ Editor in Chief: Adjunct A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand. Copy edited by Gus Mitchell/Maria McGivern. December 2018.
Giant cell arteritis is a form of vasculitis that most commonly affects the arteries of the scalp and head; as such, it is also known as temporal arteritis . Giant cell arteritis can also cause anterior ischaemic optic neuropathy, cerebral arteritis, and the aortic arch syndrome.
It is characterised by a severe headache, visual symptoms, malaise, and fever .
The incidence of giant cell arteritis ranges from 5.8 to 31.3 per 100,000 of the population, and the prevalence is estimated at 30.4 cases per 100,000 .
Giant cell arteritis occurs only in adults over the age of 50 years and peaks between the ages of 70 and 80 years . It is more frequent in women than in men and most often affects Caucasians .
In 50% of cases, giant cell arteritis is associated with polymyalgia rheumatica (PMR), a rheumatic condition that causes widespread aching and stiffness. It is estimated that 5–15% of people with PMR may develop giant cell arteritis .
Giant cell arteritis is a large vessel vasculitis of unknown cause . The symptoms of giant cell arteritis are due to occlusion of the affected arteries.
Age, genetics, and infection may be implicated in its causation . The human leukocyte antigen (HLA) DR4 serotype has been correlated with giant cell arteritis and PMR .
The clinical features of giant cell arteritis are typically :
Cutaneous manifestations of giant cell arteritis are rare and may occur months after the onset of other symptoms; these manifestations include [2,4]:
Late cutaneous manifestations include ulceration and necrosis of the frontotemporal scalp and tongue .
Giant cell arteritis may rarely affect another site, such as the lower limb, but widespread skin lesions are rare. This type of lesion are caused by occlusion of small vessels in the dermis or subcutis .
It is estimated that 13–19% of patients with giant cell arteritis experience ischaemia of an optic artery, causing sudden partial or complete vision loss that may be permanent [1,2].
Patients who develop scalp necrosis have an increased risk of vision loss and mortality .
Other complications can include gangrene of the tongue or nasal septum .
The diagnosis of giant cell arteritis is based on the clinical features and the results of investigations.
The American College of Rheumatology has suggested five criteria for the diagnosis of giant cell arteritis; these criteria are :
The presence of three or more criteria has a 93.5% sensitivity and a 91.2% specificity for the diagnosis .
The differential diagnosis for giant cell arteritis may include :
If there is a strong clinical suspicion of giant cell arteritis, systemic steroid treatment should be initiated immediately to decrease the risk of a loss of vision .
Typically, 40–60 mg of oral prednisone daily is prescribed for a minimum of 4 weeks, which may be preceded by intravenous methylprednisolone sodium succinate if there is visual impairment. The steroid dose is tapered down over 1–2 years . Bone protection, such as calcium and vitamin D supplementation or bisphosphonate medication, may be necessary for some patients due to the side effects of long-term corticosteroid use .
In some cases, adjunctive immunomodulatory medication may be used, such as methotrexate or tocilizumab .
Low–dose aspirin is prescribed concurrently to prevent ischaemic events .
Occasionally, a skin graft is required to repair persistent ulceration .
Giant cell arteritis is usually self-limiting and resolves over months to years . Relapses can occur as the corticosteroid dose is reduced and require the dose to be increased temporarily .
New-onset visual loss is rare once corticosteroid treatment is started .
Giant cell arteritis is associated with increased cardiovascular morbidity and mortality .
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