Polymyalgia Rheumatica 

Updated: May 30, 2020
Author: Ehab R Saad, MD, MA, FACP, FASN; Chief Editor: Herbert S Diamond, MD 

Overview

Practice Essentials

Polymyalgia rheumatica (PMR) is a relatively common chronic inflammatory condition of unknown etiology that affects elderly individuals. It is characterized by proximal myalgia of the hip and shoulder girdles with accompanying morning stiffness that lasts for more than 1 hour.[1] Approximately 15% of patients with PMR develop giant cell arteritis (GCA), and 40-50% of patients with GCA have associated PMR. Despite the similarities of age at onset and some of the clinical manifestations, the relationship between GCA and PMR is not yet clearly established.[2]

PMR is a clinical diagnosis based on the complex of presenting symptoms and the exclusion of the other potential diseases (see Presentation and Workup). Corticosteroids are considered the treatment of choice, and a rapid response to low-dose corticosteroids is considered pathognomonic. Patients who are at risk for relapse, have steroid-related adverse effects, or need prolonged steroid therapy may benefit from the addition of methotrexate or tocilizumab.[3]  (See Treatment.)

Patients have an excellent prognosis. Exacerbations may occur if steroids are tapered too rapidly, however, and relapse is common.

Pathophysiology

The cause of PMR is unknown. PMR is closely linked to giant cell arteritis (GCA, temporal arteritis), although it is controversial whether GCA and PMR are two separate diseases or part of the same spectrum of disease.[4] One hypothesis is that in a genetically predisposed patient, an environmental factor, possibly a virus, causes monocyte activation, which helps determine the production of cytokines that induce manifestations characteristic of PMR and GCA. However, although several infectious agents have been investigated as possible triggers, results are inconclusive.[5]

Immunogenetic studies support a polygenic basis for GCA and PMR. Occurrence in siblings and increased prevalence in those of Northern European heritage suggest a genetic role in the pathophysiology of the disease. Although most studies confirm an association between HLA-DRB1*04 alleles and GCA, the strength of this association with PMR varies between different populations. Interleukin (IL)–1 and tumor necrosis factor–alpha (TNF-α) gene polymorphisms have weak association with GCA and PMR. In Spain, an IL-6 polymorphism was associated with the expression of PMR symptoms in GCA patients. Additionally, in this Spanish population, the RANTES polymorphism was associated with PMR and not GCA.[6]

Pathologically, GCA and PMR are similar, except that significant vascular involvement does not occur in pure PMR. Synovitis, bursitis, and tenosynovitis around the joints, especially the shoulders, hips, knees, metacarpal phalangeal joints, and wrists, are seen in PMR. Inflammation is thought to start within the synovium and bursae, with recognition of an unknown antigen by dendritic cells or macrophages.[7]

Systemic macrophage and T-cell activation are characteristic of both GCA and PMR. Patients often have an elevated IL-6 level, which is likely responsible for the systemic inflammatory response in both GCA and PMR. Most studies in PMR show that a decrease in the level of circulating IL-6 correlates with remission of clinical symptoms. Data on other circulating cytokines (eg, IL-1, IL-2, TNF-α, IL-10) are too scant to draw any conclusions. However, studies do show that interferon-gamma (IFN-γ) is expressed in nearly 70% of temporal artery biopsy samples from patients with GCA but is not detected in patients with isolated PMR, suggesting IFN-γ may be crucial to the development of GCA.[5, 6, 8]

Although PMR causes severe pain and stiffness in the proximal muscle groups, no evidence of disease is present on muscle biopsy. Muscle strength and electromyographic findings are normal. Instead, the inflammation is at the level of the synovium and bursae, with MRI studies revealing periarticular inflammation as well as bursitis in the bursae associated with both the shoulder and hip girdles.[9, 10]

Some evidence suggests the presence of cell-mediated injury to the elastic lamina in the blood vessels in the affected muscle groups. A prospective study of 35 patients with isolated PMR noted vascular (18F) fluorodeoxyglucose positron emission tomography (FDG-PET) imaging at diagnosis in 31% of patients, predominantly at the subclavian arteries, but at a much lower intensity than in GCA patients. Increased FDG uptake in the shoulders was seen in 95% of the patients, in the hips in 89%, and in the spinous processes of the cervical and lumbar vertebrae (correlating with interspinous bursitis) of 51% of the patients with isolated PMR.[11]

A study of circadian variation in PMR found that plasma concentrations of IL-6, IL-8, TNF-α, and IL-4 peaked between 4 and 8 am in both untreated patients and controls, although levels of those cytokines were higher throughout the day in patients. The peak in cytokines matched the early-morning peak of pain and stiffness in untreated patients. In addition, melatonin levels were consistently higher in patients than in controls and varied with time, peaking around 2 am, suggesting that melatonin stimulates cytokine production, which in turn accounts at least partly for PMR symptoms.[12]

Etiology

The exact cause (or causes) of PMR is unknown. The disease is more common among northern Europeans, which may indicate a genetic predisposition. Other risk factors for PMR are an age of 50 years or older and the presence of GCA. PMR has been reported as a rare complication of cancer therapy with immune checkpoint inhibitors (eg, nivolumab).[13, 14]

An autoimmune process may play a role in PMR development. PMR is associated with the HLA-DR4 haplotype. A high level of IL-6 is associated with increased disease activity.

Many investigators believe that nonerosive synovitis and tenosynovitis are responsible for many symptoms of PMR.

 

Epidemiology

In the United States, the average annual incidence of polymyalgia rheumatica (PMR) is 52.5 cases per 100,000 persons aged 50 years and older. The prevalence is approximately 0.5-0.7%. In a Mayo Clinic study from 2000-2014, the overall age- and sex-adjusted annual incidence of PMR was 63.9 per 100,000 population aged ≥50 years; the incidence rate was slightly higher in those years, compared with 1970-1999.[15]

Worldwide, the frequency varies by country. In Europe, the frequency decreases from north to south, with a high incidence in Scandinavia and a low incidence in Mediterranean countries. In Italy, for example, the incidence is 12.7 cases per 100,000 persons. A  United Kingdom study found an overall incidence rate of 95.9 cases per 100 000 population.[16]  In a systematic review of case records from a large primary care practice in the UK, the prevalence of PMR in patients age 55 years and older ranged from 0.91% to 1.53%, depending on the criteria set used for diagnosis.[17]

Whites are affected more than other ethnic groups. PMR is only occasionally reported in blacks. PMR is twice as common in women.

The incidence increases with advanced age. PMR rarely affects persons younger than 50 years. The median age at diagnosis is 72 years.[18]

 

Presentation

History

Patients with polymyalgia rheumatica (PMR) were often in good health prior to disease onset, which is abrupt in about 50% of patients. In most patients, symptoms appear first in the shoulder girdle. In the remainder, the hip or neck are involved at onset. At presentation, symptoms may be unilateral but they usually become bilateral within a few weeks.

The symptoms include pain and stiffness of the shoulder and hip girdle. The stiffness may be so severe that the patient may have a great difficulty rising from a chair, turning over in bed, or raising the arms above shoulder height. Stiffness after periods of rest (gel phenomenon) as well as morning stiffness of more than 1 hour typically occurs.

Muscle weakness is not a feature of PMR. However, this can be difficult to assess in the setting of pain, especially if symptoms are protracted and untreated, resulting in disuse atrophy.

Patients may also describe distal peripheral joint swelling or, more rarely, limb edema. Carpal tunnel syndrome can occur in some patients. Most patients report systemic features as listed below.

Several diagnostic criteria for PMR exist. One set of diagnostic criteria is as follows[19] :

  • Age of onset 50 years or older
  • Erythrocyte sedimentation rate ≥40 mm/h
  • Pain persisting for ≥1 month and involving 2 of the following areas: neck, shoulders, and pelvic girdle
  • Absence of other diseases capable of causing the same musculoskeletal symptoms
  • Morning stiffness lasting ≥1 hour
  • Rapid response to prednisone (≤20 mg)

In 2012, the European League Against Rheumatism and the American College of Rheumatology published new provisional classification criteria for PMR in patients aged 50 or older with bilateral shoulder aching and elevated inflammatory markers. These are not diagnostic criteria, but rather are designed for enrolling patients into clinical trials of new treatments for PMR.[20] This collaborative initiative resulted in a scoring algorithm based on the following criteria:

  • Morning stiffness >45 minutes (2 points)
  • Hip pain/limited range of motion (1 point)
  • Absence of rheumatoid factor and/or anti–citrullinated protein antibody (anti-CCP) (2 points)
  • Absence of peripheral joint pain (1 point)

A score of ≥4 points has a 68% sensitivity and 78% specificity for discriminating PMR from other comparison patients. There is also an additional ultrasound criteria (1 point if positive findings), which can add up to a score of ≥5 points that is associated with a 66% sensitivity and 81% specificity for PMR.[21]

Systemic findings in more than 50% of patients are as follows:

  • Low-grade fever and weight loss
  • Malaise, fatigue, and depression
  • Difficulty rising from bed in the morning
  • Difficulty getting up from the toilet or out of a chair
  • Difficulty completing daily life activitiesHigh, spiking fevers (rare, should prompt evaluation for underlying infection, malignancy, or vasculitis)

Musculoskeletal findings are as follows[22] :

  • Morning stiffness for ≥1 hour, often more prolonged
  • Muscle stiffness after prolonged inactivity
  • Synovitis of proximal joints and periarticular structures
  • Peripheral arthritis (in 25% of patients)
  • Carpal tunnel syndrome (in about 15% of patients)
  • Distal extremity swelling (in approximately 12%)
  • Possible development of arthralgia and myalgia up to 6 months after onset of systemic symptoms

Physical Examination

PMR is a clinical diagnosis based on the complex of the presenting symptoms and exclusion of the other potential diseases. The symptoms and signs of PMR are nonspecific, and objective findings on physical examination are often lacking.

General symptoms are as follows:

  • Fatigued appearance
  • Low-grade temperature
  • Distal extremity swelling with pitting edema

Musculoskeletal findings are as follows:

  • Normal muscle strength; no muscle atrophy typically present at initial presentation
  • Pain in the shoulder and hip with movement; active range of motion may be decreased because of pain
  • Transient synovitis of the knee, wrist, and sternoclavicular joints; a more peripheral nonerosive arthritis may be seen in some cases
  • Tenderness to palpation with decreased active range of motion in the musculature of the proximal hip/leg and/or shoulder/arm girdle

In later stages, disuse muscle atrophy with proximal muscle weakness may occur. Contractures of the shoulder capsule may lead to limitation of passive and active movements.

 

DDx

Diagnostic Considerations

Problems to be considered in the differential diagnosis of polymyalgia rheumatica include the following:

  • Acute or chronic infection

  • Infective endocarditis

  • Bursitis/tendinitis

  • Cervical spondylosis

  • Dermatomyositis

  • Malignancy

  • Myopathy

  • Parkinson disease

  • Remitting seronegative symmetrical synovitis with pitting edema (RS3PE)

  • Shoulder disorders (eg, shoulder synovitis, rotator cuff tendinitis, and subdeltoid bursitis)

  • Calcium pyrophosphate deposition disease

  • Late-onset ankylosing spondylitis

  • Vasculitis (eg, giant cell arteritis)

Differential Diagnoses

 

Workup

Approach Considerations

Joint guidelines from the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) recommend performing the following laboratory studies in all patients with polymyalgia rheumatica (PMR), both to help to exclude mimicking conditions and to establish a baseline for monitoring therapy[23] :

  • Rheumatoid factor and/or anti-cyclic citrullinated peptide antibodies (anti-CCP)
  • C-reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR)
  • Complete blood cell count (CBC) with differential
  • Blood glucose
  • Serum creatinine
  • Liver function tests
  • Bone profile (including calcium and alkaline phosphatase)
  • Dipstick urinalysis

Additional studies to consider are as follows[23] :

  • Protein electrophoresis
  • Thyroid-stimulating hormone (TSH)
  • Creatine kinase
  • Vitamin D

If clinically indicated, tests such as the following may be considered to exclude alternative diagnoses[23] :

  • Antinuclear antibodies (ANA)
  • Anti–cytoplasmic neutrophil antibodies (ANCA)
  • Tuberculosis tests
  • Chest radiographs

The ESR is a sensitive diagnostic study for PMR, but it is not specific. The ESR is frequently greater than 40 mm/hr, but it can exceed 100 mm/hr. The ESR is mildly elevated in 7-20% of patients. Occasionally, the ESR is normal; this may occur in patients with limited disease activity.[24] In these cases, the diagnosis is based on rapid positive response to low-dose oral corticosteroids (10-15 mg/day).

The CRP level is often elevated and may parallel the ESR. Longitudinal studies suggest that CRP may be a more sensitive test than ESR for the diagnosis of PMR

The CBC reveals mild normocytic, normochromic anemia in most patients. The white blood cell count may be normal or mildly elevated. Platelet counts are often increased, reflecting systemic inflammation.

Liver function tests reveal normal transaminase enzyme levels. Alkaline phosphatase may be mildly increased in approximately one third of patients. The serum albumin level may be slightly decreased.

The creatine kinase level is normal; this finding helps differentiate PMR from polymyositis and other primary myopathic disorders.

Antinuclear antibodies, complement, rheumatoid factor, and anti-CCP levels are usually normal. The serum interleukin-6 (IL-6) level is elevated and often closely parallels the inflammatory activity of the disease; however, this test is not readily available in most laboratories. Plasma fibrinogen assays are widely available, and elevation in the plasma fibrinogen level has been recommended for the diagnosis of active PMR, with subsequent decreases used for confirmation of response to treatment.[25]

In a study of serum markers related to immune cells that may be involved in PMR and giant cell arteritis (GCA), serum B-cell activating factor (BAFF) and IL-6 were most strongly associated with disease activity in both GCA and PMR patients. Serum CCL2, CCL11, IL-10, and sIL-2R were modulated in GCA patients only, while CXCL10 was modulated in PMR patients only. The study population comprised 24 newly diagnosed, untreated GCA/PMR patients; 14 corticosteroid-treated GCA/PMR patients in remission; and 13 controls.[26]

In patients who have synovitis with effusions, synovial fluid analysis reveals signs of mild inflammation, including poor mucin clotting. Synovial fluid WBC counts range between 1,300-11,000 cells/µL (median 6,000 cells/µL), with 34% polymorphonuclear leukocytes (range 12-78%).

Imaging studies

Radiographs reveal either normal joints or evidence of osteoarthritis. Evidence of erosive arthritis should prompt evaluation for other disorders such as rheumatoid arthritis or crystalline arthritis. Magnetic resonance imaging (MRI) is not necessary for diagnosis, but MRI of the shoulder reveals subacromial, subdeltoid bursitis and glenohumeral joint synovitis in the vast majority of patients. MRI of the hands and feet demonstrates inflammation of the tendon sheaths in many patients.

In a Japanese study, MRI of the shoulder showed a significantly thicker supraspinatus tendon and more frequent severe rotator cuff tendinopathy in patients with PMR than in patients with rheumatoid arthritis or controls. In both shoulder and hip joint MRIs, effusion around the joints was greater in PMR patients, and periarticular soft tissue edema was significantly more frequent.[27]

Ultrasonography is operator-dependent but may be useful when the diagnosis is uncertain. Bursa ultrasonography may reveal an effusion within the shoulder bursae. The ultrasonography findings and those of MRI usually correlate well.[28]

Symptomatic vasculitis in cranial and extracranial vessels is rare in PMR, but a study by Kermani et al demonstrated subclinical involvement in about one third of patients using ultrasonography and positron emission tomography (PET) scanning.[29] In a study of 18F-fluorodeoxyglucose (FDG)-PET/CT, Wakura et al reported abnormal FDG accumulation at the entheses, suggesting that enthesitis may be a feature of PMR and that its presence can help differentiate.PMR from elderly-onset rheumatoid arthritis.[30]   

A joint international guideline on functional FDG-PET combined with anatomical CT angiography concluded that FDG-PET imaging has high diagnostic value for the detection of large-vessel vasculitis (ie, Takayasu arteritis and GCA) or PMR and has an important role in the diagnosis of extracranial vascular involvement in these patients, although there are no definitive consensus criteria for the presence of vascular inflammation with FDG-PET in these disorders.[31]

Temporal Artery Biopsy

Temporal artery biopsy (TAB) has a very low yield in patients with isolated polymyalgia rheumatica (PMR) and is therefore usually unnecessary in patients with PMR who do not have symptoms of giant cell arteritis (GCA). TAB is not indicated in patients with mild symptoms of PMR that is of recent onset or in patients who have remained stable over a long period (1 year or longer without current or previous clinical evidence of arteritis).

Patients should be monitored for symptoms or signs of GCA after treatment initiation because low-dose corticosteroids do not prevent progression of PMR to GCA. TAB should be considered if clinical signs of vasculitis develop, if clinical response is incomplete with low doses of prednisone (≤20 mg/d), and/or if the ESR or CRP remains elevated or rises despite symptom resolution on corticosteroid therapy. Low-dose corticosteroids do not appear to affect biopsy yield.

 

Treatment

Approach Considerations

Polymyalgia rheumatica (PMR) is a chronic, self-limited disorder. Therapy is based on empiric experiences because few randomized clinical trials are available to guide treatment decisions. The therapeutic goals are to control painful myalgia, to improve muscle stiffness, and to resolve constitutional features of the disease.

Corticosteroids (ie, prednisone) are considered the treatment of choice because they often cause complete or near-complete symptom resolution and reduction of the erythrocyte sedimentation rate (ESR) to normal. However, no definite evidence demonstrates that corticosteroids (or any other therapy) alter the natural history of PMR. Before the corticosteroid era, patients with PMR occasionally experienced spontaneous improvements, and musculoskeletal symptoms were treated with nonsteroidal anti-inflammatory drugs (NSAIDs). The low-dose corticosteroids used in PMR are almost certainly ineffective in the prevention of vasculitis progression.

Joint guidelines from the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) conditionally recommend starting corticosteroid therapy with 12.5-25 mg/day of prednisone or the equivalent.[23] A systematic examination of the peer-reviewed literature, which included 30 studies, found that remission of PMR seemed to be achieved for most patients with a starting dose of prednisone at 15 mg/day. A slow tapering of the prednisone, less than 1 mg/month, was associated with fewer relapses. Once prednisone is tapered to 10 mg/day, a slow taper by 1 mg every 2 months until treatment discontinuation was associated with optimal control of disease activity.[32]

Nevertheless, controversy remains regarding dose and duration of treatment. Dose depends on the patient's weight and severity of symptoms. Expect prompt relief of symptoms within 24-72 hours. Corticosteroid dose should be increased if symptoms are not well controlled within 1 week, and a diagnosis of giant cell arteritis may need to be pursued, especially if prednisone 20 mg/d does not control symptoms. In contrast to other rheumatic diseases, alternate-day administration of corticosteroids in PMR has largely been unsuccessful.

Tapering should be guided by clinical response to include decreased pain and stiffness, decreased morning stiffness, and decreased shoulder pain/limitation on clinical examination.[33, 34] Normalization of inflammatory markers is also helpful but should not be used as a guideline for decreasing or stopping treatment. Patient-reported outcomes including global pain, hip pain, morning stiffness, physical function, mental function, as well as inflammatory markers have been reported as the best measures of disease activity and response to treatment.

If not contraindicated, NSAIDs may provide supplemental pain relief. However, per a study of 232 patients with PMR by Gabriel and colleagues, NSAIDs are associated with considerable drug-related morbidity and thus should be used with caution.[35]

Corticosteroid-sparing agents are sometimes considered in patients with PMR to reduce corticosteroid-related adverse effects, especially in certain patient populations such as diabetic patients or in those who develop osteonecrosis.

Methotrexate has been investigated in three randomized studies in newly diagnosed PMR. One study used methotrexate at 7.5 mg/week plus 20 mg/day of prednisone and found no benefit in outcomes after 2 years of follow-up.[36] Another study used oral and intramuscular methotrexate at a higher dose of 10 mg/week added to the prednisone regimen versus prednisone regimen alone. Overall, the patients receiving methotrexate 10 mg/week plus prednisone experienced corticosteroid-sparing effects.[37, 38]  A retrospective study of methotrexate in 100 patients with relapsed or steroid-resistant PMR reported benefit with doses of up to 20 mg/day.[39]

Limited but increasing data on tocilizumab, an interleukin-6 receptor antagonist, suggest that this agent is effective, safe, and well-tolerated in patients with PMR and has a robust steroid-sparing effect.[40] Early evidence also supports tocilizumab monotherapy as first-line treatment for PMR, instead of steroids.[41]

Tumor necrosis factor alpha (TNF-α) inhibitors have also been investigated as corticosteroid-sparing agents in PMR. A randomized study with infliximab revealed no benefit.[42] The only randomized trial using azathioprine (150 mg/d) during the maintenance phase of PMR showed a high frequency of adverse drug effects and a high number of patient withdrawals from the study, although a lower cumulative dose of corticosteroid at 52 weeks. At this time, the small number of completers and the high number of giant cell arteritis patients in the study make the study results difficult to interpret.[43] EULAR/ACR guidelines strongly recommend against the use of TNF-α inhibitors in PMR.[23]

Symptomatic palliation of pain with analgesic therapy alone with close monitoring may be preferable in patients with intolerable adverse effects from corticosteroids (eg, uncontrolled diabetes mellitus, severe symptomatic osteoporosis, psychosis).

Diet and Activity

Calcium and vitamin D supplementation should be initiated in all patients with PMR who are starting corticosteroid therapy.

Generally, activity restriction is unnecessary. Physical therapy is recommended for those with difficulty achieving good mobility despite adequate medical therapy.

Consultations and Long-Term Monitoring

Diagnosis and treatment involve the primary care physician and rheumatologist. In coordination with the primary care physician, the rheumatologist plays an important role in the diagnosis, treatment, and follow-up care. Ophthalmologists, pathologists, and surgeons may be consulted on an as-needed basis should concern arise about the development of giant cell arteritis.

Involvement of primary care providers is imperative, to assist with the management of comorbidities such as prophylaxis for cardiovascular disease, glucocorticoid-induced hyperglycemia, and osteoporosis. Appropriate immunizations should be administered, ideally before corticosteroid therapy is initiated.

PMR is typically treated in an outpatient setting. Determination of prognosis and of duration of treatment remain empiric and patients often need careful supervision.

Patients receiving steroids should have monthly follow-up, with regular monitoring of inflammatory markers. An isolated increase of ESR without symptoms during the course of treatment is not a valid reason to increase corticosteroid dose; however, a temporary delay in dosage reduction may be necessary. After steroid tapering, follow-up can be performed quarterly.

The risk of vertebral fractures is five times greater in women with PMR. A baseline bone mineral density study (eg, dual-energy x-ray absorptiometry [DEXA] scan) is recommended at the onset of treatment. As most patients require corticosteroids for at least 1-2 years, bisphosphonate therapy is recommended to prevent corticosteroid-induced osteoporosis. Interestingly, in an Italian, study, PMR patients who were treated with bisphosphonates were more likely to be able to discontine corticosteroids.[44]

Because relapses are more likely to occur during the initial 18 months of therapy and within 1 year of corticosteroid withdrawal, with a frequency of approximately 50%, all patients should be monitored for symptom of recurrence throughout corticosteroid tapering and for 12 months after cessation of therapy.

Relapses usually occur when the dose of prednisone is less than 5.0-7.5 mg/day or after therapy has been discontinued. If symptoms recur, the corticosteroid dose should be increased to the dose that previously controlled the symptoms. Recurrences of the disease more than 1 year after discontinuation of corticosteroid therapy has been reported.[45]

Approximately 50-75% of patients can discontinue corticosteroid therapy after 2 years of treatment. However, some patients may require low doses of corticosteroids for several years. In a population-based study from the United Kingdom, the median duration of  continuous corticosteroid treatment was 15.8 months, but around 25% of patients received more than 4 years in total of corticosteroid therapy.[16]

Patients with PMR should be monitored regularly and carefully for symptoms and signs suggestive of GCA development.

 

Guidelines

Guidelines Summary

The following organizations have issued guidelines on the management of polymyalgia rheumatica (PMR):

  • European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR)
  • Italian Society of Rheumatology

Diagnosis

Both the Italian Society of Rheumatology and the joint EULAR/ACR guidelines recommend that following a clinical diagnosis of PMR, an evaluation should be performed to exclude mimicking conditions and to establish a baseline for monitoring therapy. This workup should include the following tests[23, 46] :

  • Rheumatoid factor and/or anti-cyclic citrullinated peptide antibodies (anti-CCP)
  • C-reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR)
  • Complete blood cell count (CBC) with differential
  • Blood glucose
  • Serum creatinine
  • Liver function tests
  • Bone profile (including calcium and alkaline phosphatase)
  • Dipstick urinalysis

Additional studies to consider are as follows[23] :

  • Protein electrophoresis
  • Thyroid-stimulating hormone (TSH)
  • Creatine kinase
  • Vitamin D

If clinically indicated, tests such as the following may be considered to exclude alternative diagnoses[23] :

  • Antinuclear antibodies (ANA)
  • Anti–cytoplasmic neutrophil antibodies (ANCA)
  • Tuberculosis tests
  • Chest radiographs

The Italian Society of Rheumatology also recommends assessing for the following conditions that can affect the management of PMR[46] :

  • Hypertension
  • Diabetes
  • Glucose intolerance
  • Cardiovascular disease
  • Dyslipidemia
  • Peptic ulcer
  • Osteoporosis
  • Cataracts and glaucoma
  • Chronic or recurrent infections
  • Concurrent therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) and other medications
  • Risk factors for steroid-related adverse effects

Consultation with a specialist should be considered if the patient has any of the following[46] :

  • An atypical presentation (eg, peripheral inflammatory arthritis, systemic symptoms, low inflammatory markers, or age < 60 years)
  • Adverse effects of therapy (or high risk for adverse effects)
  • PMR that resists glucocorticoids, relapses, or requires a prolonged course of treatment

Treatment

The joint EULAR/ACR guidelines include the following key treatment recommendations[23] :

  • Glucocorticoids are the preferred treatment.
  • Short-term NSAIDs and/or analgesics may be used to treat pain related to comorbid conditions such as osteoarthritis.
  • Initial glucocorticoid therapy should be 12.5-25 mg/day of prednisone or the equivalent. 
  • Intramuscular methylprednisolone may be considered as an alternative to oral glucocorticoid therapy.
  • Early introduction of methotrexate (MTX) in addition to glucocorticoid therapy, is conditionally recommended for patients at high risk of relapse and/or prolonged therapy, as well as in those with risk factors for adverse effects of glucocorticoid therapy.
  • Use of MTX may be considered during follow-up in patients with a relapse, lack of a significant response to glucocorticoid therapy, or development of glucocorticoid adverse events.

The Italian Society of Rheumatology guidelines concur with the recommendations for initial glucocorticoid therapy and the addition of MTX in patients at high risk for relapse, prolonged therapy, and/or steroid-related adverse events.[46]

The EULAR/ACR guidelines recommend individualized glucocorticoid dose-tapering schedules, based on regular monitoring of disease activity, laboratory markers, and adverse events.[23]   Both guidelines agree that the target dosages for tapering are 10 mg/day of prednisone or the equivalent within 4-8 weeks. If relapse occurs, increase to the pre-relapse dosage and decrease gradually (within 4-8 weeks) to the dosage at which the relapse occurred. Once remission of PMR is achieved, taper the dosage by 1 mg every 4 weeks (or by 1.25-mg decrements using schedules such as 10/7.5 mg on alternate days) until treatment is discontinued.[23, 46]

The Italian Society of Rheumatology and EULAR/ACR guidelines recommend against the use of tumor necrosis factor alpha (TNF-α) inhibitors.[23, 46]

An exercise program to help maintain muscular mass and function and reduce the risk of falls, particularly in frail patients with PMR and in older patients who are receiving long-term glucocorticoid therapy, is recommended by both guidelines.[23, 46]

Monitoring and Surveillence

The guidelines concur that regular monitoring includes clinical assessment and laboratory studies, on the following schedule[46] :

  • Every 4-8 weeks in the first year of treatment
  • Every 8-12 weeks in the second year
  • As indicated, in case of relapse or as prednisone is tapered off
 

Medication

Medication Summary

The goals of therapy in polymyalgia rheumatica (PMR) are to control painful myalgia, to improve muscle stiffness, and to resolve constitutional features of the disease. Oral corticosteroids are the first line of treatment. Nonsteroidal anti-inflammatory drugs (NSAIDs) may be helpful as adjuncts to corticosteroids during tapering, or alone in mild cases; however, because they are associated with increased drug-related morbidity, they should be used with caution, especially in elderly patients. Steroid-sparing agents may be beneficial.

The interleukin-6 receptor antagonist tocilizumab is approved for use in giant cell arteritis and has demonstrated benefit for PMR in several case series and retrospective studies.[47] However, controlled trials are needed to fully establish the efficacy of tocilizumab in PMR, and it has not yet been approved for this indication by the US Food and Drug Administration.

 

Corticosteroids

Class Summary

These agents cause profound and varied metabolic effects. Their exact mechanism of action in PMR is not well known, but their efficacy may stem from their general anti-inflammatory and immunomodulatory effects. In addition, corticosteroids down-regulate cytokine production.

Prednisone (Deltasone, Rayos)

Prednisone has the capacity to dramatically reduce inflammatory manifestations. Polymyalgia rheumatica is rapidly responsive to low doses of prednisone. However, patients may require treatment for several months to several years.

Prednisolone (Orapred ODT, Veripred 20, Millipred, Millipred DP)

Corticosteroids act as potent inhibitors of inflammation. They may cause profound and varied metabolic effects, particularly in relation to salt, water, and glucose tolerance, in addition to their modification of the immune response of the body. Alternative corticosteroids may be used in equivalent dosage.

Nonsteroidal Anti-Inflammatory Drugs

Class Summary

These agents can be administered to some patients with mild symptoms; however, patients require corticosteroids for total control of symptoms. NSAIDs may be helpful in later stages of corticosteroid dosage tapering, with close monitoring for drug-related morbidity. NSAIDs generally have no effect on the ESR.

Ibuprofen (I-Prin, Motrin, Caldolor, NeoProfen, Advil, Provil)

Ibuprofen is the drug of choice for patients with mild to moderate pain. It inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis.

Naproxen (Anaprox DS, Aleve, Naprosyn, Naprelan)

Naproxen is indicated for relief of mild to moderate pain. It inhibits inflammatory reactions and pain by decreasing activity of cyclooxygenase, which results in a decrease of prostaglandin synthesis.

Ketoprofen

Ketoprofen is used for relief of mild to moderate pain and inflammation. Small dosages are indicated initially in small patients, elderly patients, and patients with renal or liver disease. Doses higher than 75 mg do not increase the therapeutic effects. Administer high doses with caution, and closely observe the patient’s response.

Indomethacin (Indocin, Tivorbex)

Indomethacin is used for relief of mild to moderate pain; it inhibits inflammatory reactions and pain by decreasing the activity of COX, which results in a decrease of prostaglandin synthesis.

Diclofenac (Cambia, Zipsor, Zorvolex, Dyloject)

Diclofenac inhibits prostaglandin synthesis by decreasing COX activity, which, in turn, decreases formation of prostaglandin precursors.

Antineoplastics, Antimetabolite

Methotrexate (Trexall, Xatmeb, Otrexup, Rasuvo, Rheumatrex)

Antineoplastic agent that is immunosuppressive at lower doses. Antirheumatic effects may take several weeks to become apparent. Unknown mechanism of action in treatment of inflammatory disorders; may affect immune function. Ameliorates symptoms of inflammation (eg, pain, swelling, stiffness).

 

Follow-up

Further Outpatient Care

Joint guidelines from the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) recommend regular monitoring that includes clinical assessment and laboratory studies, on the following schedule[23] :

  • Every 4-8 weeks in the first year of treatment
  • Every 8-12 weeks in the second year
  • As indicated, in case of relapse or as prednisone is tapered off

Complications

PMR usually has a limited course of several months to 5 years. Untreated patients often feel unwell and have an impaired quality of life, but generally, PMR is not associated with serious complications. Patients treated with corticosteroids are at risk for long-term complications of corticosteroid therapy.

Relapses are common and may occur in up to 25% of all treated patients. Arteritic relapse in a patient who presented exclusively with PMR is unusual. 

Every patient should be considered at risk for giant cell arteritis (GCA). 

Several cases of systemic amyloidosis–associated PMR have been reported. Rare cases of bilateral ocular inflammation (episcleritis, scleritis, or anterior uveitis) developing during steroid tapering have been reported.[48]

Prognosis

PMR is usually self-limited. With prompt diagnosis and adequate therapy, the condition has an excellent prognosis.

Patient Education

Inform the patient about the potential benefits and risks of corticosteroids treatment and encourage the patient to participate in choosing the treatment plan.

Emphasize the importance of healthy dietary habits and ensure adequate calcium and vitamin D supplementation.

Emphasize compliance with long-term treatment plans and follow-up care in order to prevent relapses, flares, and subsequent morbidity secondary to corticosteroid therapy.

Advise patients to immediately seek medical care if symptoms recur.

 

Questions & Answers