Giant cell arteritis (GCA) is the most common of the systemic vasculitides [ 1 ]. GCA is also a classic systemic rheumatic disease of older adults; it virtually never occurs in individuals younger than 50 years of age and peaks in incidence in the seventh decade [ 2 ]. Although all ethnic groups can be affected, most patients with GCA are white [ 3 ]. Many of the symptoms and signs of GCA result from involvement of the cranial branches of arteries that originate from the aortic arch, but, as the disease is systemic, vascular involvement can be widespread.
Polymyalgia rheumatica (PMR) is a condition that occurs in women more than men, who are usually in their 70s. The condition involves muscle discomfort, soreness, and stiffness in the neck, shoulders, upper arms, hips, and upper thighs. The cause of PMR is unknown but it’s sometimes related to a viral illness that may cause the immune system to increase inflammation. There are some people who’ll have temporal arteritis and also develop symptoms of PMR, and how and why the two conditions overlap is unknown. Both conditions respond to oral steroids. It is estimated that roughly 711,000 people have PMR and 228,000 have temporal arteritis.
At present, prednisone remains the standard of care for GCA. While it works very well, there are many side-effects of this medication. Other immune suppressing medications have been tried but do not work very well for this condition. Methotrexate, a medication commonly used for treatment of rheumatoid arthritis, is sometimes used to help reduce the risk of disease flares. Other treatments are currently being investigated. The types of inflammatory cells that are involved in the arteritis are being identified in current research. Understanding the nature of the inflammatory processes may lead to improved treatment.