Introduction
Giant cell arteritis (GCA), often referred to as temporal arteritis and polymyalgia rheumatica (PMR), is a common inflammatory disease that is strongly linked to those over the age of 50. The temporal artery is the main target of GCA; however, it can also irritate arteries in other regions of the body. It is the most prevalent primary vasculitis in the older population and can cause blindness if it is not identified and treated very once. Ten percent of people with PMR also have GCA, and around fifty percent of those with GCA also have PMR. The forearms, hands, calves, and feet are frequently spared from participation in PMR, which typically manifests as significant stiffness and discomfort in the muscles of the girdle (including the neck, shoulders, buttocks, and thighs). PMR can cause serious disability if untreated.
What Are Giant Cell Arteritis (GCA) And Polymyalgia Rheumatica (PMR)?
Giant cell arteritis (GCA) is characterized by inflammation that adversely affects arteries, particularly those of larger and medium sizes. These arteries play a vital role in transporting blood and essential nutrients from the heart to various tissues throughout the body. Notably, some of the arteries impacted by GCA supply blood to the head, including the temples, which is why the condition is sometimes referred to as cranial or temporal arteritis.
Polymyalgia rheumatica (PMR) is a condition whose name can be broken down for better understanding: "polymyalgia" literally means "many muscle pains," while "rheumatica" implies a state of fluctuation or change. PMR is characterized by severe stiffness and pain predominantly in the muscles of the girdle, such as the neck, shoulders, buttocks, and thighs, with sparing of the forearms, hands, calves, and feet.
What Are the Risk Factors for Polymyalgia Rheumatica and Giant Cell Arteritis?
The likelihood of developing polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) is influenced by specific risk factors, including:
- Age: These conditions predominantly affect individuals over the age of 50, with a higher incidence among those in their late 60s and 70s.
- Sex: Women are more prone to these disorders compared to men.
- Ethnic and Racial Background: While more commonly observed in Caucasians, particularly those of Northern European descent, PMR and GCA can also occur in individuals from various ethnic and racial backgrounds.
What Is the Pathogenesis of Polymyalgia Rheumatica and Giant Cell Arteritis?
Both GCA and PMR are diseases that affect older people, and even though scientists are not exactly sure how they happen, they seem to involve similar things inside the body, like special immune cells, certain molecules in our genes, and inflammation caused by a type of cell called macrophages. As they have so much in common regarding how they affect the body, some doctors think they might actually be different forms of the same disease.
- In Giant Cell Arteritis (GCA): In GCA, not only do blood vessels get inflamed, but the whole body can become inflamed, too. When doctors look at blood vessels in GCA, they often see signs of inflammation in the layers that make up the vessel walls, which can make the vessels get narrower or even blocked. This can cause problems because the narrowed blood vessels cannot supply enough blood to areas further away from the blockage. Giant cell arteritis (GCA) primarily impacts the blood vessels in the vicinity of the neck and head, potentially resulting in manifestations such as head pain, discomfort during chewing, scalp tenderness, and, occasionally, vision impairment. But GCA can actually affect blood vessels anywhere in the body, not just in the head and neck.
- In Polymyalgia Rheumatica (PMR): In PMR, the most noticeable thing is that the whole body becomes inflamed, but the blood vessels themselves do not show any obvious signs of inflammation when doctors check. So, while GCA causes inflammation in both the blood vessels and the body, in PMR, it is mainly the body-wide inflammation that is the problem. This can make the muscles in the shoulders, neck, buttocks, and thighs really painful and stiff.
What Are the Common Symptoms of Polymyalgia Rheumatica (PMR) And Giant Cell Arteritis (GCA)?
Polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) are related conditions, and some individuals may experience symptoms of both. Approximately ten percent of people with PMR also have GCA, and about 50 percent of those with GCA also have PMR. Symptoms of Polymyalgia rheumatica (PMR) include:
- Pain and stiffness in the neck, upper arm, shoulder, and hip regions could persist for an hour or more, often intensifying during the morning or following periods of rest. These symptoms can make everyday activities like getting out of bed or dressing difficult, and raising the arms above the shoulders may be challenging.
- Flu-like symptoms include weakness, loss of appetite, low-grade fever, and weight loss.
- Intermittent inflammation of the wrist or hand joints.
- PMR symptoms can develop rapidly, sometimes within a few days or even overnight.
Symptoms of Giant Cell Arteritis (GCA) include:
- Headaches and tenderness in the scalp, with severe pain often located in the temple areas.
- Jaw pain, particularly during chewing.
- Visual disturbances, such as double vision or vision loss in one or both eyes. These visual problems may initially be brief but require immediate medical attention because untreated GCA can lead to permanent vision loss in a matter of hours or days.
- Flu-like symptoms include a low-grade fever, weakness, loss of appetite, and weight loss.
- GCA can also impact major blood vessels, resulting in complications such as the dilation of the aorta (aneurysms) or discomfort in the arms or legs during physical activity due to blockages in the arteries. In some cases, aorta inflammation may not cause noticeable symptoms but can be detected through imaging tests.
What Are the Causes of Polymyalgia Rheumatica and Giant Cell Arteritis?
Inflammation is the underlying mechanism behind polymyalgia rheumatica and giant cell arteritis, yet the precise triggers remain unidentified. While some research has identified potential genetic associations with these disorders, these links have not demonstrated consistent patterns across various populations. Furthermore, given that these conditions predominantly affect older individuals, the aging process itself may play a role in their onset.
How Are Polymyalgia Rheumatica and Giant Cell Arteritis Diagnosed?
Giant Cell Arteritis: The diagnosis of GCA is typically suspected when a patient presents with the aforementioned symptoms. While laboratory tests can aid in the diagnostic process, they are not conclusive on their own. A test commonly used for this purpose is the ESR (erythrocyte sedimentation rate), which assesses how quickly red blood cells and other particles settle in a tube. A notably rapid or elevated rate often corresponds to ongoing inflammation. However, it is important to note that while the ESR test is informative, it is not infallible, and the diagnosis of GCA may still be made even when the test results are within the normal range.
The definitive diagnosis of GCA can only be achieved through a temporal artery biopsy. This procedure entails a small incision at the temple, from which a segment of the artery is extracted and subsequently examined under a microscope. Upon suspicion of GCA, it is crucial to promptly initiate treatment. The temporal artery biopsy can be conducted after treatment commencement. Delaying treatment until after the biopsy can carry risks, as complications of the disease, such as permanent vision loss, may develop in the interim. Therefore, swift intervention is essential to safeguard the patient's well-being.
Polymyalgia Rheumatica: Diagnosing polymyalgia rheumatica (PMR) involves:
- Reviewing the patient's medical history, emphasizing pain, stiffness, and affected areas.
- Conducting a thorough physical exam to identify PMR features and rule out other conditions.
- Excluding other illnesses through blood tests.
- Interpreting blood test results, including the erythrocyte sedimentation rate (ESR).
- Confirming PMR if symptoms rapidly improve with low-dose corticosteroid treatment.
What Is the Treatment for Polymyalgia Rheumatica (PMR) And Giant Cell Arteritis (GCA)?
Treatment for both polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) involves managing symptoms since there is no known cure. The primary treatment for PMR and GCA is corticosteroid medication. It helps quickly alleviate symptoms. For GCA, it is crucial to prevent severe complications like blindness. Lower corticosteroid doses are often effective for PMR, while higher doses are needed for GCA.
Corticosteroids mimic a natural hormone called cortisol and reduce inflammation. They also weaken the immune system. The decision to use steroids depends on factors like age, other health conditions, and medications. Regular check-ups and blood pressure monitoring are essential because steroids can increase infection risk. Report any new symptoms to the doctor.
To counteract bone weakening caused by steroids, some patients may need calcium, vitamin D, and bone density testing. Long-term steroid treatment requires close monitoring due to potential side effects. The doctor will gradually reduce the dose when the condition stabilizes. Some patients may eventually stop steroid treatment altogether. In some cases, daily low-dose aspirin may be recommended to reduce vascular complications, but not everyone can take it due to allergies or other medications.
Conclusion
In conclusion, giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are autoimmune diseases without a known treatment but are well controlled with corticosteroids, with greater dosages being required for GCA. These drugs reduce inflammation and inhibit the immune system to relieve symptoms. Due to potential adverse effects, such as infection risk and bone thinning, regular monitoring is essential. Once symptoms are under control, steroid dosages are gradually decreased, and some patients may eventually stop taking medication. In some circumstances, taking low-dose aspirin can help prevent vascular problems. Individuals can successfully manage chronic disorders and retain a high quality of life with appropriate medical care and adherence to treatment plans, emphasizing the significance of regular interaction with healthcare professionals.
