Giant Cell (Temporal) Arteritis
Overview
Plain-Language Overview
Giant Cell (Temporal) Arteritis is an inflammatory condition that affects the large and medium-sized arteries, especially those in the head such as the temporal arteries. It primarily involves the blood vessels supplying the scalp and eyes, which can lead to symptoms like headache, scalp tenderness, and vision problems. This condition mainly affects older adults and can cause serious complications if untreated, including vision loss. The inflammation causes the arteries to become swollen and narrowed, reducing blood flow. Early diagnosis and treatment are important to prevent permanent damage. The disease is also known as temporal arteritis because of its common involvement of the temporal artery.
Clinical Definition
Giant Cell (Temporal) Arteritis is a systemic vasculitis characterized by granulomatous inflammation of large and medium-sized arteries, predominantly the extracranial branches of the carotid artery, including the temporal artery. The pathogenesis involves a T-cell mediated immune response leading to infiltration of the vessel wall by multinucleated giant cells, macrophages, and lymphocytes, causing intimal hyperplasia and luminal narrowing. It is the most common form of vasculitis in adults over 50 years old and is closely associated with polymyalgia rheumatica. Clinically, it presents with new-onset headache, jaw claudication, scalp tenderness, and visual disturbances due to ischemia. The major clinical significance lies in the risk of irreversible vision loss from anterior ischemic optic neuropathy if untreated. Elevated inflammatory markers such as ESR and CRP are typical laboratory findings.