, David G. I. Scott2 and Chetan Mukhtyar2
(1)
Department of Rheumatology, Ipswich Hospital NHS Trust, Ipswich, UK
(2)
Department of Rheumatology, Norfolk and Norwich University Hospital, Norwich, UK
Electronic supplementary material
The ownline version of this chapter (doi:10.1007/978-3-319-14871-7_5) contains supplementary material, which is available to authorized users.
5.1 Introduction
Giant cell arteritis (GCA) is the most common systemic vasculitis in the elderly. It is characterized by the involvement of the large vessels, predominantly the extracranial branches of the aorta. There is a close relationship with polymyalgia rheumatica (PMR). The first description of GCA was provided by Sir Jonathon Hutchinson in 1890, who described a patient at the London Hospital who could not wear a hat because of painful red streaks on his head. The painful streaks were thickened temporal arteries with feeble pulsations. The full description of the condition was provided by Bayard Horton in 1932.
5.2 Definition and Classification
The 2012 Chapel Hill Consensus conference defined GCA as “Arteritis, often granulomatous, usually affecting the aorta and/or its major branches, with a predilection for the branches of the carotid and vertebral arteries. Often involves the temporal artery. Onset usually in patients older than 50 years and often associated with polymyalgia rheumatica” [1].
The ACR in 1990 developed a classification criteria, which are widely used in clinical trials (Table 5.1). A classification of GCA requires three of the five criteria. They have a specificity of 91.2 % and sensitivity of 93.5 % [2]. There are no validated diagnostic criteria.
Table 5.1
ACR criteria for the classification of GCA
Age at onset >50 years |
Development of symptoms or findings beginning at 50 years or older |
New headache |
New onset of, or new type of, localized pain in the head |
Temporal artery abnormality |
Temporal artery tenderness to palpation or decreased pulsation, unrelated to atherosclerosis of the cervical arteries |
Increase in erythrocyte sedimentation rate (ESR) |
ESR >50 mm/h by Westergren method |
Abnormal artery biopsy |
Biopsy specimen with an artery showing vasculitis characterized by a predominance of mononuclear infiltration or granulomatous inflammation |
5.3 Epidemiology
GCA is more common among people of north European descent than among Mediterranean people and is rare among African Americans, native Americans, and Asians. GCA occurs in individuals older than 50 years and the age-adjusted (>50) annual incidence in the UK is 22/100,000 population [3]. The annual incidence rates per 100,000 population rises from 2 in the sixth decade to 52 in the ninth decade [4]. The estimated prevalence is about 1:750 persons older than 50 years. There is a female preponderance; women are two to three times more commonly affected.
5.4 Etiology
The etiology is unknown. There is an association with HLA DRB*0401. Although infectious triggers have long been suspected, no clear associations have yet been confirmed. A proposed hypothesis suggests that the arterial wall dendritic cells become activated and then recruit CD4+ lymphocytes, which become clonally expanded producing IL-2 and IFN-γ. Macrophages produce PDGF, which stimulates intimal arterial thickening. Subsequently, monocyte and macrophages become multinucleate giant cells.
5.5 Clinical Features
The onset of symptoms may be abrupt. Some patients may recall the exact date and hour their symptoms started. In most instances, symptoms are insidious and develop gradually over several weeks.
5.5.1 Systemic
Constitutional features, including fever, fatigue, anorexia, weight loss, and depression are present in the majority of patients. Patients may present with pyrexia of unknown origin.
Myalgia and arthralgia with morning stiffness across the shoulder and hip girdle is suggestive of coexistent PMR.
5.5.2 Craniofacial
Headache is the most common symptom occurring in >60 % of patients. It is typically felt over one or both of the temporal areas. Less commonly the headache may be generalized or occipital. Important features of the headache are that it is different in nature from previous headaches, can be severe or paroxysmal, and be associated with scalp tenderness. Wearing a hat or glasses or combing the hair may be uncomfortable. In severe cases, involvement of the scalp arteries may lead to segmental scalp necrosis (Fig. 5.1).
Figure 5.1
Scalp necrosis in a patient with giant cell arteritis
Jaw claudication (30 %), pain in the tongue or jaw during mastication, which resolves with rest may be a risk factor for neuro-ophthalmic complications. In rare cases tongue infarction may result from ischemia.
The temporal arteries may be tender nonpulstaile and thickened (Fig. 5.2). Bruits may be audible over affected arteries especially in the axillae.
Figure 5.2
Swollen temporal artery in a patient with giant cell arteritis
5.5.3 Ophthalmic
Ophthalmic manifestations are common and may result in blindness. Acute visual loss occurs in as many as 20 % of patients. The visual loss is usually sudden, painless, and permanent. Visual disturbance may vary from mistiness of vision or involvement of part of the visual field to complete blindness. Visual loss may be bilateral. There may be premonitory symptoms such as blurry vision, amaurosis fugax, visual hallucinations, and diplopia in up to 50 % of cases. These premonitory signs may precede visual loss by several days and should be considered a medical emergency in GCA, as prompt treatment may prevent the development of irreversible blindness.