Definition and Overview
Giant cell arteritis is a systemic vasculitis that causes granulomatous inflammation in the walls of medium to large arteries. It invades extracranial arteries, including the temporal artery, and the aorta and its major branches. It is the most common vasculitis that occurs in people over 50 years of age, and if not treated, it is an emergency disease that can progress to irreversible vision loss due to ischemic optic neuropathy.
Giant cell arteritis is closely related to polymyalgia rheumatica, and the two diseases often appear together.
Epidemiology
Giant cell arteritis occurs, almost without exception, in people over the age of 50, and the incidence increases with age, reaching a peak in people in their 70s. It occurs more commonly in women than in men. The incidence is reported to be high in the Nordic population.
symptoms
New-onset temporal headaches are the most common symptom and are often localized to the temples. It is accompanied by tender scalp that feels painful when brushing or putting your head on the pillow.
Jaw claudication, which causes pain and fatigue in the jaw muscles while chewing food, is a symptom strongly suggestive of giant cell arteritis. Visual disturbances can begin with temporary loss of vision and progress to permanent vision loss in one or both eyes. It may be accompanied by systemic symptoms such as fever, weight loss, and malaise, as well as pain and stiffness in the shoulder and pelvic area due to polymyalgia rheumatica.
diagnosis
Diagnosis is a combination of clinical symptoms, inflammatory markers, imaging, and tissue findings.
- Inflammatory markers: Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are common.
- Temporal artery ultrasound: Check for halo sign, which suggests edema of the blood vessel wall.
- Temporal artery biopsy: This is a standard test to check for granulomatous inflammation and giant cells in the blood vessel walls.
- Imaging tests: CT, MRI, PET, etc. are used to evaluate the presence or absence of invasion of the aorta and its major branches.
The 1990 American College of Rheumatology classification criteria include onset over age 50, new-onset headache, temporal artery abnormality, elevated ESR, and biopsy abnormality.
treatment
For giant cell arteritis, preventing vision loss is the top goal of treatment. If clinically suspected, initiate high-dose glucocorticoids immediately without waiting for biopsy results. If visual disturbances are present, consider administering a higher dose of intravenous steroids.
Steroids are gradually reduced once symptoms are controlled, and interleukin-6 inhibitors such as tocilizumab are sometimes used together to reduce recurrence during the reduction process and long-term steroid side effects.
Clinical implications
New-onset temporal headaches, jaw claudication, and visual disturbances after the age of 50 are warning signs of giant cell arteritis. Delayed diagnosis can lead to permanent blindness, so it is important to quickly start treatment and conduct tests at the suspected stage.