What is Rheumatic Polymyalgia?
Rheumatic polymyalgia (RP) is a systemic inflammatory disease of the elderly, characterized by pain and stiffness in the muscles of the shoulder and pelvic girdle in combination with fever, weight loss, depression, high rates of activity of the process in laboratory studies and often with signs of temporal arteritis.
The epidemiology of RP has been studied only in the last 10-15 years in the USA and Sweden. It is established that the distribution of RP ranges from 133 to 28.6 per 100,000 population over 50 years. Many researchers believe that RP is not less common than ankylosing spondylitis, gout, SLE.
People over 50 years old with an age peak at the age of 65-75 years fall ill. Women get sick more often than men.
The pathomorphology of RP is practically not studied, since a biopsy of painful muscles, as a rule, does not reveal any significant changes. A biopsy of the synovial membrane and periarticular tissues often reveals signs of nonspecific synovitis and periarthritis.
A frequent combination of RP with temporal arteritis was the basis to suggest that the symptoms of polymyalgia are due to vascular lesion – an oaxial process in the aortic wall and branches extending from it, especially the arteries of the upper half of the trunk, neck, and head. Indeed, signs of RP can be detected in about half of patients with temporal arteritis, confirmed by biopsy of the temporal artery, and in one third of these patients, symptoms of RP precede the appearance of signs of temporal arteritis.
Causes of Rheumatic Polymyalgia
The possible role of a viral infection, as well as stressful situations, hypothermia, acute respiratory infections.
Symptoms of Rheumatic Polymyalgia
In most patients, RP begins acutely, with severe pain and stiffness, mainly in the muscles of the neck and shoulder girdle, less often (in one third of patients) in the muscles of the pelvic girdle, hips. N.V. Bunchuk and S. S. Nikitin noted characteristic pain in RP, which has a certain diagnostic value. Localization of pain – the neck, shoulder joints and shoulders, buttocks, hips. The pains are usually cutting, pulling, twitching, the intensity of which is associated with the activity of the disease. Myalgia and stiffness intensify in the morning, with any movement, at night in those muscle groups that are under stress, including body weight. It is characteristic that the pain does not bother the patient at rest, when taking a comfortable position. Myalgia and stiffness are usually symmetrical, accompanied by limited movement in the shoulder and hip joints, cervical spine. Noteworthy is the mismatch between the severity of subjective sensations and the absence of soreness or slight soreness during palpation of these areas. So, in most cases, it is not possible to detect significant changes in the shoulder and hip joints, periarticular tissues, with the exception of slight pain on palpation of the muscles and tendon-ligamentous apparatus, in particular in the region of the large tubercle of the humeral head, sternoclavicular and clavicular acromial joints. There is no atrophy or infiltration in the muscles of the shoulder or pelvic girdle.
Active movements in the cervical spine, in the shoulder and hip joints are sharply limited, so it is difficult for patients to dress, comb, wash, squat, get up from a low chair, go up and down the stairs. The gait changes, the step becomes shallow, mincing. It is extremely important that passive movements are limited to a lesser extent than active ones. Non-steroidal anti-inflammatory drugs or analgesics reduce myalgia only for a short time, while prednisone even in small doses (10-15 mg / day) has a quick clinical effect.
Of the other manifestations of RP, it is necessary to note arthritis, to which attention was paid only in recent years after examination of patients by scintigraphy. L. A. Healey most often found signs of arthritis in the shoulder, sternoclavicular, wrist and knee joints. Arthritis is usually unstable and is easily stopped by intraarticular administration of hydrocortisone or by taking GCS inside.
The above symptoms are accompanied, as a rule, by general weakness, loss of appetite, weight loss, fever. The severity of these signs is usually associated with the activity of the disease.
A number of patients reveal tachycardia, pain during palpation along large arterial trunks. In a number of cases, pain in the limbs takes on a peculiar character, paresthesia, sensations of chilliness, numbness appear, which, as a rule, are associated with the development of temporal arteritis. Temporal arteritis is also manifested by headache, sensitivity during palpation of the scalp, especially temporal arteries, and visual impairment. Headache is usually one-sided, severe, most severe at night. It can begin suddenly and in about one third of patients is the first symptom of the disease. The pain often radiates from the temporal region to the neck, lower jaw, eyes, ears, simulating maxillofacial neuralgia, temporomandibular joint arthritis, or even a brain tumor. When examining the temporal artery, you can find a painful compaction of the walls of the vessels and the absence of their pulsation, swelling of the tissues surrounding the artery. In almost half of patients with temporal arteritis, vision is impaired. It gradually or suddenly decreases, a number of patients develop diplopia, and approximately 10% may cause blindness in one or both eyes as a result of ischemic optic neuropathy or hemorrhagic changes in the retina. The sudden development of cerebral disorders, impaired patency of the great vessels (pulse asymmetry, pressure, vascular murmurs) are of important diagnostic value.
Of the laboratory tests for RP, the most important is the increase in ESR, sometimes reaching 60-80 mm / h. Many patients have a small normochromic anemia (100-110 g / l). A high level of fibrinogen, a2globulin, SRV and other acute phase proteins can be stated. RF, AHA are not determined, the level of antistreptolysin is normal.
During the electromyographic study of the muscles in the area of which the pain was noted, no significant changes were detected, however, a small degree of decrease in the average duration of the potentials of the motor muscles or single fibrillation potentials are occasionally recorded.
Diagnosis of Rheumatic Polymyalgia
When recognizing RP, some help is provided by the diagnostic criteria proposed by B. Hamrin:
- the patient is older than 50 years;
- the presence of muscle pain in at least two of the three areas (neck, shoulder and pelvic girdle);
- bilateral pain localization;
- the prevalence of the specified localization of pain during the active phase of the disease;
- ESR more than 35 mm / h;
- the duration of the symptoms of the disease is at least 2 months;
- restriction of movements in the cervical spine, shoulder and hip joints;
- general weakness, fatigue, anorexia, weight loss, fever, anemia.
The first five criteria are considered mandatory, the rest are optional.
The presence of temporal arteritis in a patient with RP can be judged by detecting changes in the arteries of the temporal region, pain on palpation, lack of pulse, circulatory disturbance in the area of a particular major vessel extending from the aortic arch. Positive findings are found with positive findings during biopsy of the temporal artery.
It should be borne in mind the “dumb” forms of RP, in which there is no myalgic syndrome, and there are only asthenia, depression, severe violations of laboratory tests.
The absence of specific signs of the disease often poses the clinician the task of diagnosing RP by eliminating those diseases that are found in the elderly – systemic vasculitis, polymyositis, RA, systemic polyosteoarthrosis, paraneoplastic syndromes, polyneuropathy, etc.
The impression of the possibility of a patient with polymyositis is created in connection with the development of RP immobility. However, the latter is due not to myasthenia characteristic of polymyositis, but only to myalgia. Patients with RP do not have amyotrophy, increased serum creatine phosphokinase, and severe creatinuria. In contrast to RP, with polymyositis, the content of acute phase blood proteins, like ESR, is moderately increased. In addition, small doses of prednisone for polymyositis are completely ineffective.
The combination of RP with temporal arteritis makes differential diagnosis necessary with other systemic vasculitis, but it is not difficult, if you remember the features of vascular pathology in temporal arteritis.
It may be necessary to distinguish RP from RA, which began in old age. The latter is characterized by a predominant lesion of the shoulder joints, but, as a rule, others are also involved in the process, i.e., the symptoms of polyarthritis quickly develop with damage to small joints of the hands and feet and characteristic radiological changes.
Differentiation with polyosteoarthrosis is difficult, since RP can be combined with it. In these cases, one should remember the peculiarities of pain in RP, the severity of signs of inflammatory activity, which is generally not characteristic of polysteoarthrosis.
In paraneoplastic syndrome with myalgias, most often we are talking about polymyositis with characteristic myasthenia, amyotrophy, and not RP, which can be distinguished on the basis of mainly muscle pain.
Treatment of Rheumatic Polymyalgia
RP is an absolute indication for the appointment of GCS, mainly prednisolone, in small and medium doses (from 10 to 30 mg / day) fractionally (in 2-4 doses) depending on the activity of the process, i.e. the intensity of pain, the presence or absence of immobility, the degree of increase in protein content in the acute phase of the disease and ESR. In an individually selected dose, prednisone is prescribed to significantly reduce pain and laboratory indicators of the activity of the process. Then, gradually, the patient is transferred to a single morning intake of the entire overwhelming dose of prednisone and only subsequently, carefully, they begin to reduce the dose to the maintenance dose (5-10 mg / day). The patient receives this dose for several months. If possible, therapy is completed by alternating with prednisone, that is, alternating (every other day) a maintenance dose with an even smaller one, with a gradual lengthening of the interval between doses of prednisolone. Experience shows that patients are forced to take GCS for months, and often for years.
With a combination of RP with temporal arteritis, treatment is carried out according to the rules of treatment of the latter.
Additionally, in the treatment of this disease, non-steroidal anti-inflammatory drugs can be used – indo-metacin, voltaren and others in medium doses.
The prognosis for RP is satisfactory. With early recognition and adequate treatment, recovery occurs. With late recognition and irregular treatment, there may be exacerbations requiring an increase in the dose of prednisone, which is subsequently prescribed in maintenance doses for many years. In essence, this method of treatment is a means of secondary prevention of exacerbation. Primary prevention is not developed.