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Polymyalgia Rheumatica

Polymyalgia rheumatica is a clinical syndrome that consists of by muscle aching and stiffness, without weakness, that involves the neck and shoulder girdle and pelvic girdle. The disorder usually affects persons over the age of 50 years. The diagnosis is based upon careful clinical assessment, and the symptoms are controlled rapidly and dramatically with low-dose corticosteroid treatment. Polymyalgia rheumatica can be an important clue to the existence of serious Polymyalgia Rheumatica, polimyalgia, polymialgia, rumatica, polymyalgea.

Epidemiology

The average annual incidence for persons age 50 years and older is  50 cases/100,000. In the northern

Polymyalgia rheumatica clearly increases as the population ages. After the age of 80 years, the annual incidence was 78/100,000 in Goteborg and 97/100,000 in Olmsted County. Occurrence in women is about twice that in men and

Etiology

Genetic predisposition, infection, and immunological abnormalities appear to contribute to the etiology of polymyalgia rheumatica. The increased occurrence of polymyalgia rheumatica in people of northern European

Pathophysiology

Epidemiologic data suggest that an appropriate genetic background contributes to development of polymyalgia rheumatica, and an infectious agent may trigger aberrant immune responses in a susceptible individual. The disease is characterized by striking muscle stiffness and pain, and muscles may display electromyographic abnormalities (fibrillation potentials, complex repetitive discharges) that improve after treatment with corticosteroids. The

Clinical Features

The classic symptoms of polymyalgia rheumatica are muscle pain and stiffness, and these symptoms often form the basis of the chief complaint. The shoulder girdle is commonly the first area to become symptomatic, and pain is also experienced in the neck, upper back, upper arms, lower back, and hip girdle. The pain is typically severe, aching in nature, and bilateral. Pain is accentuated by movement of the joints, but the pain is not localized to the joints. The symptoms appear to arise in muscles, tendinous attachments, and

Patients have prominent stiffness, resembling that found in rheumatoid arthritis. The stiffness is present in the morning, tends to wear off with movement, and recurs later in the day if the patient is inactive. The pain and stiffness may occur so abruptly that the patient remembers the date and hour of onset, or the onset may be gradual.

Constitutional symptoms that may be associated with polymyalgia rheumatica include malaise, fatigue, weight loss, and depression. Low-grade fever has been reported in polymyalgia rheumatica, but high spiking fever suggests underlying infection or giant cell arteritis.

Patients are limited functionally due to the pain and stiffness and may describe difficulties in acts that require use of the proximal musculature (brushing the hair or teeth, rising from the supine or sitting position). It should be emphasized, however, that the muscles are not truly weak.

On physical examination, the typical patient is an elderly Caucasian with a sad and distressed facial expression. Because giant cell arteritis can occur in patients with polymyalgia rheumatica, it is a good idea to carefully palpate both temporal arteries and the branches of these vessels in the scalp. Finding normal vessels does not eliminate the possibility of arteritis. It is well recognized that involved arteries can pulsate and have no tender areas. Just the same, finding a tender segment of temporal artery can be an important clue to the presence of giant cell arteritis. A tender area is the preferred location for an arterial biopsy.

The musculoskeletal examination usually reveals normal muscle bulk, tone, and strength. Tenderness may be elicited over the paracervical muscles and the glenohumeral joints. Muscle testing is difficult because there is considerable pain with movement. If the patient has not moved the painful shoulders for a period of months, the result will likely be restriction of active and passive abduction, elevation, internal rotation, and external rotation.

Synovitis should be sought on the physical examination, because about one-fourth of patients have evidence of peripheral arthritis at the onset of disease. Careful palpation of the sternoclavicular joints, wrists, metacarpophalangeal joints, and knees may reveal swelling and tenderness.

A newly recognized finding is diffuse swelling with pitting edema that can involve hands or feet. The involved areas are painful, and pain is intensified when joints in the area are moved. The swollen part is occasionally warm but not erythematous. The swelling often extends beyond joint margins and occasionally follows tendons. Distal extremity swelling with pitting edema reflects synovial inflammation in joints and tenosynovial membranes.

Carpal tunnel syndrome can be a "hidden" manifestation of polymyalgia rheumatica and has been reported as the

Diagnostic Criteria

In 1979, Bird reported a collaborative study in which 146 patients with polymyalgia rheumatica in Great Britain were compared with 253 other patients whose diseases resembled polymyalgia rheumatica. It was proposed that patients having three of seven criteria had polymyalgia rheumatica with 92% sensitivity and 80% specificity. (See Table 2) Other sets of published diagnostic criteria have emphasized the diagnostic importance of pain, recent onset of symptoms, elevated ESR, morning stiffness, older age (over 50 years), systemic symptoms such as weight loss and fever, elevation of acute phase reactants other than the ESR, and muscle tenderness.

An important finding in polymyalgia rheumatica is that treatment with low doses of corticosteroids (10-20 mg prednisone a day) produces prompt relief of symptoms. This response is so predictable and dramatic that some authors consider it a diagnostic criterion.



Table 2. Diagnostic Criteria for Polymyalgia Rheumatica
• Bilateral shoulder pain and stiffness

• Onset of illness within two weeks

• Initial ESR higher than 40 mm/hour

• Morning stiffness exceeding one hour

• Age older than 65 years

• Depression and/or loss of weight

• Bilateral upper arm tenderness

Any three criteria discriminated between polymyalgia rheumatica and other conditions with sensitivity of 92% and specificity of 80%.


Adapted from Cimmino MA, Salvarani C. Polymyalgia rheumatica and giant cell arteritis. Balliere's Clin Rheumatol 1995;9:515-527 and based upon data in Bird HA, et al. An evaluation of criteria for polymyalgia rheumatica. Ann Rheum Dis 1979;38:434-439.

Differential Diagnosis

The diagnosis of polymyalgia rheumatica is based on clinical findings with supportive data from laboratory tests. It is a diagnosis of exclusion, in that the clinician must rule out a wide variety of diseases that can present with constitutional symptoms, proximal myalgias, and high ESR. Diseases that mimic polymyalgia rheumatica are listed in Table 3.

Table 3. Differential Diagnosis: Diseases that can Mimic Polymyalgia Rheumatica
• Rheumatoid arthritis and RS3PE syndrome

• Myopathies (inflammatory, drug-induced)

• Systemic lupus erythematosus

• Hematopoietic malignancies

• Multiple myeloma, macroglobulinemia of Wadenstrom, myelodysplastic syndromes, lymphoma

• Paraneoplastic syndromes

• Renal cell carcinoma

• Adenocarcinomas (uterus, stomach, pancreas, colon, prostate, unknown origin)

• Infections (subacute bacterial endocarditis, viral infection, Lyme disease)

• Amyloidosis

• Hypothyroidism

• Bone pain (metastatic cancer, metabolic bone disease)

• Fibromyalgia


Adapted from Brooks RC, McGee SR. Diagnostic dilemmas in polymyalgia rheumatica. Arch Intern Med 2002; 157:162-168 and from data published in references 5, 47, 49, and 50.

Elderly-onset rheumatoid arthritis, with onset at 60 years of age or older, can have an abrupt polymyalgia-like onset. The shoulders and hips are involved early, the metacarpophalangeal joints may be spared, and subcutaneous nodules appear to be less common than in younger rheumatoid arthritis patients. The ESR tends to be high with elderly onset. If the test for rheumatoid factor is negative, it may be impossible to differentiate elderly-onset rheumatoid arthritis from polymyalgia rheumatica until the patient has been observed for 6-12 months. Response to low-dose oral prednisone, 5-15 mg daily, is excellent. Some clinicians believe that efficacy of second-line remittive agents is reduced, and these drugs may be more toxic in the elderly rheumatoid arthritis patient.

The elderly patient who presents with bilateral pitting edema of the hands and/or feet, joint pain, and an elevated ESR is a diagnostic puzzle. The possibilities that need to be considered are polymyalgia rheumatica with distal pitting edema and remit-ring seronegative symmetrical synovitis with pitting edema (RE3PE). Polymyalgia rheumatica can be associated with distal pitting edema that results from synovial inflammation in the joints and about tendons. This finding was reported in 19 (8%) of members of a population cohort of 245 patients with polymyalgia rheumatica. The soft tissue swelling usually developed gradually, involved both sides, and was present in

Therapy of Polymyalgia Rheumatica

The original series of patients reported by Barber included two patients who responded to phenylbutazone and three patients who had spontaneous remission. No patients received corticosteroids. Some patients have responded to NSAIDs. Chuang described 96 patients with polymyalgia rheumatica who were identified in a 10-year period in

There may be a role for NSAID treatment in selected patients with mild polymyalgia rheumatica, but many clinicians believe that low-dose prednisone is the treatment of choice. NSAID treatment often fails. In about two-thirds of individuals who receive aspirin or other NSAIDs initially, it is necessary to switch to corticosteroids in order to

A starting dose of 5-20 mg of prednisone a day is usually effective. Occasionally, a dose of 25 mg is required. Behn examined the prospective course of treated polymyalgia rheumatica. The corticosteroid dose was regulated with a

Patients should remain on the starting dose of prednisone for a minimum of four weeks. The rate of dose taper is guided by the clinical response. Resolution of symptoms is more important than reduction in the ESR. For those

Patients whose disease is not controlled, or who have significant corticosteroid side effects, should be considered for treatment with a steroid-sparing drug. In one series, 65% of polymyalgia rheumatica patients treated with an average