What is Polymyalgia Rheumatica?
Polymyalgia rheumatica (PMR) is a disease that affects people over 50, causing stiffness and pain in the neck, shoulders and hips. Today it is known that the symptoms are caused by inflammation in the deep joints of the shoulder, neck and hip. The stiffness can be so intense that it can incapacitate the patient. Other symptoms are: fatigue, weight loss, low fever, and depression.
They are still unknown, however the high incidence after 50 years suggests that it is somehow related to the aging process.
PMR rarely occurs before age 50, and the average age of people with these diseases is approximately 70 years, and is twice as common in women as in men.
The diagnosis of PMR is eminently clinical, with history, physical examination and laboratory tests helping to rule out other conditions that can cause similar symptoms. The diagnosis is made when there is evidence in the history and physical examination, and an important change in the tests that indicate inflammation, such as the erythrocyte sedimentation rate (ESR) and C-reactive protein. These tests are elevated in several causes of inflammation, and are not specific for PMR, and should always be interpreted in the clinical context.
The goal in the treatment of PMR is to alleviate symptoms with improved quality of life. Typically, patients with PMR respond very well to small doses (5 – 10 mg) of Prednisone, which is a corticosteroid). Treatment often lasts for two years or more, and it is necessary to control the effects of using prednisone over this time, with progressive dose reduction. In some cases, a “corticosteroid-sparing” medication, such as methotrexate, is used to allow a safer reduction in prednisone.
Relationship between polymyalgia rheumatica and giant cell arteritis (ACG)
About 20% of patients with PMR have an inflammatory process in some arteries, a condition known as giant cell arteritis (ACG), also known as temporal arteritis, due to the high frequency of involvement of the arteries in the regions of the temples. This inflammation leads to a narrowing of the artery, sometimes with a complete blockage of the blood vessel, resulting in a lack of whole blood from the area of the body irrigated by the artery. The main symptom is a new headache. When ocular arteries are involved, blindness in one or both eyes can happen suddenly. Strokes are also not uncommon. Mandibular pains when chewing or talking, as well as pain in the temporal arteries are some of the symptoms that usually occur.
A biopsy of the temporal artery may be necessary to close the diagnosis of ACG. A difference in temporal artery pulse on palpation strongly suggests the diagnosis, and more recently, ultrasound (ultrasound) of the temporal arteries has been widely used for diagnosis.
It is very important to know if the patient with PMR also has ACG, because the dose of prednisone to be used in arteritis is higher, around 40 to 60mg per day. This dose is necessary to avoid the main complication, blindness. Generally, if the patient with PMR does not show signs of headache, visual changes, pain in the temporal artery or pain when chewing, the chance of giant cell arteritis is very small.