What a mouthful “Polymyalgia Rheumatica” is. This disorder and the closely related giant cell arteritis, are both autoimmune diseases that fall under the category of inflammatory diseases. They are called inflammatory diseases because they are the result of activation of the normal inflammatory response that is necessary in fighting disease. The only problem is that in these diseases, the immune system has turned against the body, rather than fighting off invading infection. Giant cell arteritis is discussed elsewhere, so here we focus on Polymyalgia Rheumatica.
The term Polymyalgia Rheumatica, abbreviated PMR, describes the symptoms of the disease. “Poly” means many and “myalgia” refers to muscle pain. “Rheumatica” is simply a derivation of rheumatoid, which refers to pain and stiffness of the joints and extremities. Thus, but the words together and you get pain of many muscles and joints. This is exactly what Polymyalgia Rheumatica is. Common symptoms include a keen and pain in the muscles of the neck, shoulders, back, hips, dies, and occasionally the trunk. In general, the pain of Polymyalgia Rheumatica is found and the muscles of the shoulder and pelvic girdles, those muscles important for posture. People often find it difficult to do common tasks such as rising from a chair or lifting their arms above their head. Other less specific symptoms include a weight loss, anorexia, and a general feeling of illness. almost never affects anyone under the age of 50.
Polymyalgia Rheumatica is a disease of inflammation. In this case, the inflammation occurs in the blood vessels and muscles. Giant cell arteritis is closely related, but in giant cell arteritis the inflammation is predominantly in the blood vessels. In Polymyalgia Rheumatica the inflammation is primarily to be found in the muscles. There is no test that is specific to PMR. Diagnosis is made based on symptoms, a few blood tests, and response to steroids. If your doctor suspects PMR, he will likely obtain an erythrocyte sedimentation rate or ESR. The ESR is a blood test that measures the general level of inflammation in the body. Normal values are generally between 15 and 20, while the ESR may be as high as 60 to 100 in PMR. If the ESR is not elevated, then PMR is most likely not the diagnosis, but an elevated ESR is not definitive.
If your symptoms fit and you have an elevated ESR, your doctor will likely start you on prednisone, a type of corticosteroid. Corticosteroids are not like the anabolic steroids used to build muscle, but are used to fight inflammation. If PMR is the correct diagnosis, you will see immediate results with complete resolution of symptoms in 12 to 48 hours. If you do not see resolution of symptoms, then PMR is not the right diagnosis and further testing should be pursued.
Now, side effects of steroids like prednisone are significant and include such things as weight gain, bone loss, and increased susceptibility to infection. So, while these drugs work well at treating PMR, it is important to reduce the dose as much as possible. Now, PMR is not cured by steroids. Steroids simply put the disease into remission, or a state in which there are no symptoms and no progression of the disease. It is a state of dormancy for the disease. The problem with PMR is that it often returns when steroids are stopped completely. So, while some people may only take steroid for a short time, it is likely that you will need to take them for several years, if not forever. After just discussing the complications associated with steroids, this may not sound like a good option. Unfortunately, there is no alternative treatment for PMR and its complications so steroids are the only option. Your doctor will likely begin with a fairly high dose of prednisone, somewhere in the range of 60 mg/day. After 4 to 6 weeks, he will begin to slowly reduce the dose of prednisone while monitoring you for relapse of symptoms. It is unlikely that you will be able to completely stop taking the steroids, but you could be weaned down to a very low dose. It is important to keep in mind the following things about steroids. First, the rate and severity of side-effects is related to the dose. The lower the dose, the fewer and less severe the side effects are.
Second, the rate of complications is related to the duration of treatment. In other words, side effects are not immediate, but rather accumulate over time while you are taking the steroid. Short courses of steroids usually do not cause any problems. In fact, once you stop taking the steroid you will return to baseline, without any further complications. If you are on long term steroid therapy, your doctor may suggest “drug holidays.” On a drug holiday, the medication is stopped if possible and you are allowed to return to baseline. Once you are at baseline, you start taking the steroid again and it is as if you had never been on it in the first place. You are right back where you started before ever taking the drug.
The third thing you should remember about steroids is that there are drugs available to treat the side-effects. So, while the best option is not to take them of course, if you are stuck taking steroids for long periods of time, other medications can be added to prevent the side effects. These medications include the bisphosphonates, like Fosamax, which prevent bone loss. Your doctor will be able to help you weigh the risks of steroids with the benefits of being disease free and with the addition of other medications, help you to find an acceptable balance.
More information about Polymaylagia Rheumatica can be found at www.arthritis.org.
Source: Chapter 21 – Vasculitides: C. Giant Cell Arteritis, Polymyalgia Rheumatica, and Takayasu’s Arteritis. In: Klippel JH. Primer on the Rheumatic Diseases 12th ed. Arthritis Foundation: Atlanta, GA; 2001. p401 – 402.