Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are distinct yet related inflammatory conditions that primarily affect older adults. Both conditions involve the body’s immune system mistakenly attacking healthy tissues, leading to inflammation.
Understanding Giant Cell Arteritis and Polymyalgia Rheumatica
Giant cell arteritis, also known as temporal arteritis, is an inflammatory condition that affects large and medium-sized arteries, particularly those in the head, such as the temporal arteries. The inflammation causes these arteries to swell and narrow, which can restrict blood flow. This condition can lead to various symptoms depending on which arteries are affected.
Polymyalgia rheumatica is an inflammatory disorder characterized by widespread muscle pain and stiffness, predominantly affecting the shoulders, neck, and hip areas. The discomfort from PMR is often most pronounced in the morning or after periods of inactivity.
GCA and PMR frequently occur together. About 15-20% of individuals with PMR also develop GCA, and roughly 50% of those diagnosed with GCA also have PMR. While PMR often appears before GCA, it can also develop concurrently. Both conditions are more prevalent in individuals over the age of 50, with the average age of onset typically around 70 years. Women are also more commonly affected by both conditions than men.
Common symptoms for GCA include new-onset headaches, which are often severe and localized to the temples, scalp tenderness, and jaw pain or fatigue when chewing. Some individuals may also experience vision changes, such as temporary vision loss or double vision. In contrast, PMR symptoms primarily involve stiffness and aching in the shoulders and hips, which can make daily activities challenging. While both conditions cause inflammation, the specific areas of the body they impact and the resulting symptoms help differentiate them.
Identifying Giant Cell Arteritis
Identifying giant cell arteritis requires prompt medical evaluation due to the potential for serious complications. A doctor will typically begin by reviewing an individual’s symptoms and conducting a physical examination, often focusing on the temporal arteries on the sides of the head. Palpation of these arteries might reveal tenderness, thickening, or a reduced pulse. Blood tests are frequently used as an initial step to detect inflammation within the body.
Common blood tests include the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), both of which are markers for inflammation and are usually elevated in individuals with GCA. However, these tests are not specific to GCA and can be elevated in other inflammatory conditions. Imaging studies, such as color duplex ultrasonography, magnetic resonance imaging (MRI), or positron emission tomography (PET) scans, can also provide valuable information by visualizing inflamed arteries. These imaging techniques can identify areas of vessel wall thickening or inflammation.
The definitive diagnostic procedure for GCA remains a temporal artery biopsy, which involves surgically removing a small segment of the temporal artery. This tissue sample is then examined under a microscope for characteristic signs of inflammation, including the presence of giant cells. While less invasive methods are improving, the biopsy is still considered the gold standard for confirming the diagnosis.
Managing Giant Cell Arteritis and Polymyalgia Rheumatica
The primary treatment approach for both giant cell arteritis and polymyalgia rheumatica involves the use of corticosteroids, such as prednisone. These medications work by suppressing the immune system and reducing inflammation throughout the body. For GCA, high doses of corticosteroids are typically initiated immediately to prevent severe complications, particularly vision loss. The dosage is then gradually reduced over an extended period, which can last for several months to a few years.
For PMR, lower doses of corticosteroids are generally effective in managing symptoms, with a similar tapering schedule once symptoms improve. The tapering process must be slow and carefully monitored by a healthcare professional to avoid disease relapse. Abruptly stopping corticosteroids can lead to a resurgence of inflammation and symptoms.
In some cases, if individuals cannot tolerate the side effects of high-dose corticosteroids or experience frequent relapses, other medications may be introduced. Immunosuppressants like methotrexate or biologics such as tocilizumab, which targets a specific inflammatory pathway, can be used as steroid-sparing agents. These medications help to reduce the overall corticosteroid dose needed, mitigating long-term side effects. Regular follow-up appointments with a healthcare provider are important to monitor disease activity, adjust medication dosages, and manage any potential side effects. Supportive care measures, including pain management strategies and physical therapy, can also help individuals with PMR alleviate muscle stiffness and improve mobility.
Potential Complications and Long-Term Outlook
Untreated or inadequately managed giant cell arteritis carries a significant risk of severe and permanent complications due to reduced blood flow to affected areas. One of the most feared complications is permanent vision loss, which can occur suddenly and is often irreversible, resulting from inflammation of the arteries supplying the eyes. Additionally, GCA can increase the risk of stroke if arteries supplying the brain are affected. Inflammation of the aorta, the body’s main artery, can also occur, potentially leading to an aortic aneurysm or dissection, which are life-threatening conditions.
Prompt diagnosis and immediate initiation of treatment are therefore very important to prevent these serious outcomes. For both GCA and PMR, the long-term outlook generally involves a period of treatment, followed by a potential for remission, where symptoms resolve. However, both conditions can recur, requiring renewed treatment. Ongoing follow-up with healthcare providers is necessary to monitor for any signs of relapse or new complications.
Long-term corticosteroid use, while effective, can lead to various side effects. These may include bone density loss (osteoporosis), increased risk of infections, weight gain, and elevated blood sugar levels. To mitigate bone density loss, doctors often recommend calcium and vitamin D supplementation. Regular monitoring of bone density and general health is part of the long-term management plan for individuals receiving corticosteroid therapy.