Polymyalgia Rheumatica (PMR)
Definition
Polymyalgia Rheumatica (PMR) is a chronic, episodic, inflammatory disease of the large arteries that usually develops in people over 50 years of age. Polymyalgia rheumatica and temporal arteritis are believed to represent the same disease process, with slightly different symptoms.
Description
Polymyalgia rheumatica (PMR) is a poorly understood pain syndrome that occurs primarily in people over the age of 50. It occurs at least twice as frequently in women as in men, and is relatively common throughout Europe and the United States. Pain and stiffness predominate in the shoulder and hip girdles, along with systemic symptoms, such as fatigue, weight loss and low-grade fever. The syndrome was probably first reported more than 100 years ago under the colorful name senile rheumatic gout. Various other names were used until 1957, shortly after an association was noted between PMR and giant cell arteritis (GCA; aka temporal arteritis). Since the 1950's, it has become apparent that PMR is relatively common and that it is indeed associated with GCA, though either disorder occurs in the absence of the other.
Causes
The etiology and pathogenesis of PMR are unknown.
Symptoms
Typically, PMR has an abrupt or rapid onset that begins with a severe, deep, aching rheumatic pain in the shoulder and pelvic area. The pattern of pain is usually symmetric and may be aggravated by the motion of joints in the vicinity. However, pain may occur at rest, and frequently awakens the patient during the night. Patients have trouble combing their hair, putting on a coat, or getting up out of a chair. A few patients have joint swelling, usually of the knees, wrists and sternoclavicular (mid and upper chest) joints. A number of systemic complaints may occur, including fever (usually low-grade), malaise, fatigue and weight loss. Findings on physical examination are typically nonspecific. When synovitis (an inflamed joint) is detected, almost always the question of rheumatoid arthritis (RA) arises. Some degree of painful joint motion is usually found. Muscle tenderness and even joint tenderness may be noted. Unlike RA, however, muscle weakness and atrophy are usually absent, and the range of motion of joints is usually normal for the age.
Diagnosis
Laboratory findings are typically nonspecific. The most widely used acute phase indicator is a blood test known as a Rapid Westergren ESR - (Erythrocyte (red blood cell) Sedimentation Rate). Serologic studies (such as rheumatoid factor and antinuclear antibody tests) and muscle-related enzyme assays (such as creatine phosphokinase) are usually negative or normal. Occasionally, liver-function test results are abnormal. There is no true muscle weakness nor evidence of muscle disease on electromyography (EMG) or on biopsy. The diagnosis is generally based on three observations: the clinical syndrome, an elevated ESR and a response to a therapeutic trial or a low dose steroid. Response to corticosteroid therapy is typically rapid and dramatic, and clearly helps to support the diagnosis. In fact, if the patient does not improve within 72 hours of treatment with a corticosteroid, such as prednisone (10-20 mg daily), a diagnosis of PMR may be incorrect.
Treatment
PMR tends to be a self-limiting illness, but may require therapy for months or years. Precise figures are difficult to establish, but the average duration of illness is about two to four years, after which time the majority of patients are relatively asymptomatic without drug therapy. In fact, in the absence of GCA, PMR often remits with no permanent disability, except those related to drug therapy. The goal in treating PMR is to help relieve pain and stiffness. Treatment includes medications to help reduce inflammation, as well as proper exercise and rest for some people in order to maintain joint flexibility, muscle strength and function. The two groups of medications used most often to treat PMR are corticosteroids, which are cortisone-like drugs, and nonsteroidal anti-inflammatory drugs (NSAIDS). Corticosteroid drugs are strong medications that help reduce inflammation. There are many forms of corticosteroids, such as prednisone. You may need to take corticosteroids as briefly as six months or as long as one or two years. Some people may need to be treated even longer. Over a long period of time, corticosteroids can cause such side effects as weight gain, osteoporosis, increased risk of infection, cataracts, glaucoma, rounding of the face, difficulty in sleeping and high blood pressure. It is important, however, not to try to cut back the dosage without medical approval, since the symptoms can worsen. In addition to corticosteroids, the second group of drugs that may be used to treat PMR are the nonsteroidal anti-inflammatory drugs (NSAIDS). These are anti-inflammatory drugs that can also relieve pain and stiffness. NSAIDS are not as strong as corticosteroids. Sometimes, very mild cases of PMR can be treated with NSAIDS alone. Aspirin and ibuprofen are two examples of NSAIDS. Other NSAIDS are available by prescription. It is important always to take NSAIDS with food, since they can upset the stomach and cause ulcers and bleeding. Once the body responds to corticosteroids or NSAIDS, the goal is to slowly reduce the dosage to the lowest level necessary to control symptoms and prevent a relapse. This requires effective communication between the patient and doctor.
Questions
Are there any tests needed to diagnose PMR? Is it PMR and/or GCA? Will you be prescribing corticosteroids? What are the side effects? What are the chances that GCA or RA may develop?
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