Giant Cell Arteritis: Symptoms, Causes, Treatment

Giant cell arteritis (RZA) (synonyms: Arteritis temporalis; Arteriitis temporalis Horton, Giant cell arteritis, Horton’s giant cell arteritis; Large vessel vasculitis; Horton-Magath-Brown syndrome; Cranial arteritis; Horton’s disease; Polymyalgia arteriitica; Polymyalgia arteriitica with giant cells; Polymyalgia rheumatica; Giant cell arteritis n.e.c. ; giant cell arteritis in polymyalgia rheumatica; giant cell arteritis in rheumatoid polymyalgia; giant cell arteritis with arteritis temporalis; giant cell granuloarteritis; giant cell granuloarteritis; ICD-10 M31.5: giant cell arteritis in polymyalgia rheumatica) refers to the most common form of systemic vasculitis (inflammation of blood vessels) in patients over the age of 50. It belongs to the group of vasculitides (inflammation of blood vessels).

Giant cell arteritis (RZA) and Takayasu arteritis (TA) are grouped under the term “large vessel vasculitis” (GGV). Giant cell arteritis primarily affects large vessels in the head, the aorta (main artery) and its large arterial branches (branches of the carotid and vertebral arteries), and extracranial (“outside the skull“) vessels such as the extremity arteries. Smaller vessels may also be involved: Ophthalmic artery and its extraparenchymal branches, as well as the small ciliary arteries.

Giant cell arteritis (RZA) is associated with polymyalgia rheumatica (PMR) in 50-66% of cases. Ocular involvement is present in up to 70% of cases. Other comorbidities (associated diseases) include: Facial pain, osteoporosis (bone loss), hypokalemia (potassium deficiency), and numerous infectious diseases such as oral candidiasis (yeast disease of the mouth) and herpes zoster (shingles).

Sex ratio: Women are two to six times more likely to be affected than men. In many cases, a familial clustering can be recognized.

Peak incidence: Giant cell arteritis occurs almost exclusively beyond the age of 50.

The incidence (frequency of new cases) of giant cell arteritis is approximately 3.5 cases per 100,000 inhabitants per year (in Germany). The incidence is highest in women aged 70 to 79 years. There is a clear north-south gradient in Europe.

Course and prognosis: Giant cell arteritis (RZA) is an emergency. If left untreated, giant cell arteritis leads to involvement of the aorta and its side branches. This leads to various complications such as aortic aneurysm. Delayed diagnosis and therapy can thus lead to serious consequences such as irreversible loss of visual acuity. Approximately 15-20% of patients go blind before receiving therapy!Note: Clinical suspicion of giant cell arteritis is an immediate indication for treatment!Recurrence of the disease is common after reduction of glucocorticoids. The recurrence rate (rate of disease recurrence) is approximately 30%.

Comorbidity (concomitant disease):Giant cell arteritis (RZA) is associated with polymyalgia rheumatica (PMR) in 50-66% of cases.