“Extra-Cranial” Manifestations of Giant Cell Arteritis

Giant cell arteritis (GCA) is a primitive systemic vasculitis related to a sub-acute inflammatory panarteritis, histologically characterized by segmentary and plurifocal damage, with giant cells and destruction of the internal elastic lamina. GCA involves large and medium sized vessels in subjects over 50, particularly between 75 and 85, and is more common in women (7:3sex-ratio). This arteritis preferentially affects the external carotid and its branches, and more specifically the superficial temporal artery, which explains the usual clinical signs of the disease which are headaches, tenderness and sensitivity of the scalp, painful thickening of the temporal arteries associated with absence of pulsation, and jaw claudication. However, this description of GCA was enriched in 1938 by the first observations of « extra-cranial » manifestations. A diagnosis of GCA is usually suspected in the elderly subject on the association of focal signs of arteritis prevailing in the head, with a more or less febrile alteration of the general health condition and an inflammatory syndrome. The classification criteria of GCA most used are those of the American College of Rheumatology and which date back to 1990. Nevertheless, GCA, because of the potential ubiquity of the pathological process, can occur in atypical forms, which renders the etiological approach more complex. The risk is therefore a delay in diagnosis which can jeopardize the prognosis of this disease. In this chapter, we will approach different atypical aspects of GCA, which can all be inaugural of the disease, whose prognosis will depend on their early recognition. They include aorta and its main branches involvement except arteritis of the branches of the external carotid artery, heart, lung, neurologic, genital and musculoskeletal manifestations.