1990 new internationally agreed-on diagnostic criteria for ABD. These criteria include recurrent oral ulceration plus two of the following: (1) genital ulceration, (2) typical deÞned eye lesions, (3) typical deÞned skin lesions, and (4) a positive pathergy test.

The diagnosis of ABD should be considered in any young patient with bilateral and recurrent retinal vasculitis or vascular occlusion that may be associated with anterior uveitis, scleritis, or episcleritis. Fluorescein angiography may be useful in determining the extent of retinal and disk involvement. Meticulous review of systems and mucosal and skin examination are essential in establishing the diagnosis.

6.1.12 Giant-Cell Arteritis

Giant-cell arteritis, also called temporal arteritis, cranial arteritis, or granulomatous arteritis, is a systemic vasculitis of unknown etiology that involves the medium-sized extracranial arteries of the carotid circulation (superÞcial temporal, vertebral, and ophthalmic), and sometimes the aorta and its primary branches [380, 381]. Complications of this vasculitis can lead to blindness, stroke, and death. Certain clinical features, laboratory tests, and histopathological Þndings are helpful in distinguishing GCA from other vasculitides: the age at onset, temporal headache or tenderness, reduced temporal artery pulsation, transient or irreversible visual loss, polymyalgia rheumatica (PMR), an elevated ESR, and mononuclear or multinucleated giant cells in the internal elasticum of the artery wall [382].

6.1.12.1 Epidemiology

Giant-cell arteritis appears to be relatively common in Europe and in the USA, although the incidence varies with the location of the population studied. It ranges from 17 cases per 100,000 population (age 50 years or older) in Scandinavia to 0.49 cases per 100,000 in Israel [383, 384]. GCA occurs in patients over 60 years of age, women are affected about three times as often as men, and is most commonly seen in Caucasians [385].

The HLA antigens, HLA-B8 [386] and HLA-DR4 [387], may be associated with GCA more commonly than expected by chance alone; however, these associations have not been deÞnitively established [388, 389].

6.1.12.2 Systemic Manifestations

Headache, occurring in more than two-thirds of patients, is the most common systemic manifestation of GCA [390]. Bilateral or unilateral, it usually begins early in the course and is often the initial symptom. The pain is throbbing or shooting in quality, sometimes severe enough to prevent sleep [391]. It is commonly localized to the temporal or occipital areas. Other cranial symptoms, such as temporal artery or scalp tenderness and jaw claudication, are present in the majority of patients. Constitutional symptoms, including fatigue, fever, anorexia, and weight loss, may be present in about half of patients, and may be an initial Þnding of the disease [392]. Because headache, fever, fatigue, and anorexia are nonspeciÞc manifestations, many patients do not seek medical attention until more speciÞc symptoms, such as scalp tenderness or jaw claudication, appear or catastrophic vision loss occurs.

Although medium-sized extracranial arteries of the carotid circulation are the arteries most commonly affected in GCA, the aorta and its branches to the upper extremities and neck also can be involved, leading to cardiovascular and cerebrovascular disease [386, 389]. Upper extremity claudication, bruits over the carotid, subclavian, and axillary arteries, and decreased or absent pulses in the neck or arms are some of the Þndings. Angina pectoris, congestive heart failure, and myocardial infarction secondary to coronary arteritis may occasionally occur. Neurological manifestations, such as peripheral neuropathy, hemiparesis, acute hearing loss, confusion, depression, psychosis, and brainstem strokes, are not uncommon, occurring in onethird of cases of biopsy-proven temporal arteritis [393, 394].

Forty to 60 % of patients with GCA have PMR, a disorder characterized by pain and stiffness involving the neck, and the shoulder and hip girdles [395, 396]. In the majority of patients, the