Polymyalgia Rheumatica

Original Editors - Nicki Spencer from Bellarmine University's Pathophysiology of Complex Patient Problems project.

Top Contributors - Nicki Spencer, Naaike Verhaeghe, Claire Knott, Admin, Elaine Lonnemann, Kim Jackson, Rachael Lowe, Ines Musabyemariya, 127.0.0.1, Wendy Walker, Evan Thomas, Ina De Maeyer and WikiSysop  

    

Search Strategy

Databases used: PubMed, Web of Science, VUB Biblio ,google, Physiopedia, 

Keywords used: Polymyalgia Rheumatica, Reumatoid arthritis, Rheumatological diseases ,
Rheumatism

Definition/Description 

(2,22,11)

Polymyalgia rheumatica (PMR) is a rheumatic inflammatory disorder that has an unknown cause.[1] It causes inflammation of the large muscles of the body and can be accompanied by constitutional symptoms, such as malaise, fatigue, fever, and weight loss.[2] In patients with PMR, the synovial membranes and bursae that line and lubricate the joints become inflamed, causing pain and discomfort. Unlike in some other inflammatory diseases, there is no associated permanent damage to the joints or the muscles.[2]
Polymyalgia rheumatic is also known as muscular rheumatism. [11] PMR is a heterogeneous disease with a major impact on QOL. [22]

Clinically Relevant Anatomy

(36,23,38)

PMR is a condition that causes many (poly) painful muscles (myalgia) [36]. PMR is characterised by pain and stiffness in the shoulder and hip girdles and an elevated acute phase response [23]

Epidemiology/etiology

  (2,3,5,8,11,16,28)

In persons over the age of 50, PMR has a prevalence of approximately 700 per 100,00. Approximately 4 in 10,000 adults over the age of 60 develop PMR each year.       

PMR is mostly seen in persons over the age of 50, PMR has a prevalence of approximately 700 per 100,000.[3] Approximately 4 in 10,000 adults over the age of 60 develop PMR each year.[2]
The prevalence is gender dependent. Women are more suitable for this condition than men. Women are twice as likely than men attained. [11]
In the United States the lifetime risk of developing PMR is estimated at 2.43% for women and 1.66% for men. [28]

Although polymyalgia rheumatic occurs worldwide, the highest incidence is seen in Scandinavian countries and in people of the northern European descent. [16]
While the lowest incidence rates occur at the more southern European countries like Italy, and Spain. [28]

The disease is more common in Caucasian.
[28]

Much research is done, but there is still no clear cause for PMR. [11]
Certain characteristics of PMR suggest that an infectious disease could be an environmental factor. It has a very sudden onset and new cases occur in cycles, which could indicate an infection as the source.[8] Attention has been focused on Chlamydia, Mycoplasma, parainfluenza virus or parvovirus B19 as possible infections responsible for PMR.[5]
Inheritance of the disorder has been suggested due to findings in some genetic studies and the pattern seen in family histories.[8] The gene(s) that could be responsible for PMR have not been definitively identified. The HLA-DRB104 and HLA-DRB01 alleles have both been found to have a possible link to PMR and GCA[5] although this remains controversial[13] ,

There may be an imbalance between immunosuppressive T-regulatory (Treg) lymphocytes and proinflammatory T-helper 17 (Th17) cells in PMR and giant cell arteritis (GCA). The frequency of Treg cells circulating appears to be reduced in patients with PMR compared with aged-matched volunteers. While on the other hand TH17 cells appear to be increased. [28]

    

Characteristics/Clinical Presentation

     The onset of PMR is very sudden. Individuals can usually remember the exact time and day that symptoms began. Individuals often wake up one morning with extreme stiffness and soreness for no apparent reason
Synovitis and bursitis of the shoulder and hip are the cause of the patient's pain.[5]
PMR is characterized by pain and stiffness involving the shoulder girdle, proximal aspects of the arms, the neck, and pelvic girdle [17]
Symptoms are usually bilateral.[13]
Other constitutional symptoms are seen in 40-50% of patients and include[1] [13]
• stiffness after rising in the morning lasting 30 min or longer [13] or after resting
• weakness
• fatigue
• malaise
• low-grade fever
• sweats
• headache
• weight loss
• depression
• vision changes

The symptoms are characteristic , although several other autoimmune, infectious , endocrine, and malignant disorders can present with similar symptoms. Ruling out the other illnesses is very important[19]. For further information see : Differential Diagnosis.
Polymyalgia rheumatic isn’t a disorder that lasts forever. Most people suffer from the disease for 2-3 years. It is important to know that it can occur for a shorter or longer term. When you can’t reduce the use of medication or you keep on having physical complaints, it is not rare that there is something else going on. You might see the doctor again for another examination, because with this clinical representation he needs to determine whether you might have rheumatoid arthritis (RA) or osteoarthritis, instead of PMR. [11]

Differential Diagnosis

There are many conditions that can mimic PMR, like rheumatoid arthritis (RA) and spondyloarthropathies (SpA). Pain and swelling of the distal joints, like feet, hands and wrists should raise concern for an inflammatory arthritis. Some patients may present swelling and pitting edema of the hands and the feet, because of a tenosynovitits. The so called remitting seronegative symmetrical synovitis with pitting edema syndrome.[28]
The first step is to assess the patient’s symptoms including pain and stiffness in the shoulder of hip girdle ( or both) .Usually of at least one week’s , and more confidently of at least two week’s , duration; in the presence of acute inflammatory markers , including erythrocyte sedimentation rate or CRP. [19]

PMR must be differentiated from :

Rheumatological diseases
Polymalgia rheumatic
Rheumatoid arthritis
Spondyloarthropathy
Crystalline arthritis (calcium pyrophosphate disease and calcium hydroxyapatite disorders)
Remitting seronegative symmetric synovitis with pitting oedema syndrome
Connective tissue diseases
vasculitis (giant cell arteritis, antineutrophil cytoplasmic antibody-associated vasculitis).
Inflammatory myopathies (dermatomyositis, polymyositis )

Non-inflammatory musculoskeletal disorders
Rotator-cuff diseases (rotator cuff tears, rotator cuff tendinopathy )
Adhesive capsulitis
Degenerative joint disease (degeneratieve disc disease)
Fibromyalgia
Endocrinopathies
Thyroid diseases
Disorders of the parathyroid gland
Infections
Viral
Bacterial sepsis, endocarditis, disc space infection, septic arthritis
Mycobacterial – eg tuberculosis
Malignant diseases
Solid, Haematological
Miscellaneous disorders
Parkinsonism
Depression
Hypovitaminosis D
Drug-induced myopathy-eg, from statins

[19]

Polymyalgia rheumatica and Giant Cell Arteritis:

Giant cell arteritis (GCA) is an inflammatory vasculopathy that normally occurs in the medium and the large arteries The ones that are usually affected are the external carotid branches (e.g., temporal and occipital arteries), the ophthalmic, vertebral, distal subclavian, and axillary arteries, and the thoracic aorta. Vasculitis leads to luminal occlusion and therefor ischemic complications.
Approximately 50% of patients with giant-cell arteritis present with polymyalgia rheumatica before, at the time of, or after the diagnosis of vasculitis.
The inflammatory reaction in the arteries is complex and is effectively suppressed with glucocorticoid treatment. The arteritis leads to remodeling of the arterial wall, giving rise to the characteristic findings on imaging and clinical manifestations.[29]

Symptoms include[2]:
• headache or tenderness on one side of the head
• scalp tenderness
• pain in the jaw when chewing, which eases quickly when the jaw is rested
• tongue or throat pain
• sudden loss of vision or any other sudden visual problem in one eye
• weakness
• numbness
• deafness

Diagnostic Procedures Medications

   Polymyalgia rheumatica is a clinical diagnosis . At initial presentation , to think of it as a polymyalgia syndrome is helpful , and a careful history and physical examination are crucial in distinguishing it from other disorders that mimic it especially seronegative RA, PSH and a paraneoplastic syndrome. [19] [5]

Physicians will typically perform a physical exam (see below), order blood tests, and perform imaging studies to determine if the patient’s symptoms are due to some other disorder.[8]
Laboratory findings are non specific and show characteristic features of systemic inflammation. These include; anaemia, leukocytosis and raised markers of inflammation (ESR and CRP) and sometimes liver tests such as transaminases or alkaline phosphatase are raised. [13]. Some clinicians use an erythrocyte sedimentation rate (ESR) of higher than 30 or 40 mm/hr as a diagnostic criterium; however, 6-20% of patients with the disease have a normal sedimentation. [13]. Autoantibodies, including rheumatoid factor and antibody to cyclic citrullinated peptide, are usually negative , and if positive RA must be considered. Other blood tests (CK, thyroid tests,…) can be performed to exclude other disorders. [13]
On an X-Ray you can especially visualize the bones and joints. Polymyalgia rheumatic is a disorder of the muscles. So to diagnose PMR, it’s pointless to take an X-ray of the sore places of the body. Anyway, the X-ray can be used to make sure that there is no other illnesses. Usually this is then an Chest-X-Ray. [11] Echo abdomen can be performed to exclude malignancy.
Radiographs of the affected joints in PMR are only useful for excluding conditions, like degenerative joint disease or crystalline arthritis. In the classification study of the EULAR/ACR, they found a high specificity for ultrasonography for discriminating PMR from other shoulder conditions (89%), but not for discriminating PMR from RA (70%). [28]

Ultrasound of the shoulders is a useful tool in the management of patients with PMR. Shoulder abnormalities obtained by US, in particular when findings such as bursitis and tenosynovitis of the long head of the biceps tendon are found in both shoulders, occurs more frequently in patients with PMR than in controls. However, in the absence of suggestive clinical features, the presence of isolated US abnormalities should not lead to a diagnose of PMR. . [18]
Ultrasound shows characteristics pathological findings of the shoulders and hips that can help distinguish polymyalgia rheumatica from other diseases.Typically finding on ultrasound include sebdeltoid bursitis and biceps tendon tenosynovitis of the shoulders and , less frequently , synovitis of the glenohumeral joint .In the hips , ultrasound often reveals synovitis and trochanteric bursitis.Inflammatory shoulder lesions have been seen even in patients with normal erythrocyte sedimentation rates. Ultrasound may particulary useful in patients with typically proximal symptoms of polymyalgia who have a normal erythrocyte sedimentation rate. [19]

Ultrasonography of the shoulder in two patients with polymyalgia rheumatica showing bicipital tenosynovitis (short axis view) (a) and subdeltoid bursitis (b).Patients with PMR often show neck and back pain, these findings can also be found in the MRI. The MRI’s of the cervical spine and the lumbar spine in patients with newly diagnosed PMR showed evidence of cervical and lumbar interspinous bursitis. On positron emission tomography (PET) study, you can observe increased fluorodeoxyglucose (FDG) uptake in the shoulders, hips, and cervical and lumbar interspinous processes in patients with PMR.Imaging of blood vessels in patients with patients with PMR show findings of vasculitis even in patients who don’t show any symptoms of GCA.
In 50% of the cases is the biopsy of the blood vessels positive, when the ultrasonography is abnormal.[28]

Positron emission tomography in a patient with polymyalgia rheumatica showing fluorodeoxyglucose uptake in both shoulders but also in the large vessels, indicating concurrent, subclinical giant cell arteritis.A biopsy isn’t necessary it can be helpful when the patients are suspected of having an inflammatory myositis based on a clinical or laboratory evaluation.
It is suggested to do a temporal artery biopsy if the patients show symptoms of cranial, or vascular abnormalities that may suggest GCA.[28]
Response to steroids should not be used as a defining feature of PMR, as about 25% of patients continue to have pain after three weeks of treatment. [13] PMR has an excellent prognosis if diagnosis is prompt and therapy adequate. [24]

Although PMR is a diagnosis of exclusion.[3] and there is no definitive single diagnostic test to identify PMR.[4], , there are two sets of diagnostic criteria that have been created for PMR.

The Bird/Wood criteria includes[5]:
• Bilateral shoulder stiffness
• Duration onset < 2 weeks
• Initial ESR > 40 mm/hour
• Stiffness > 60 minutes
• Age > 65 years
• Depression and/or weight loss
• Bilateral upper arm tenderness
If any 3 or more of the above criteria, or greater than 1 criteria and a clinical abnormality of the temporal artery, are present in a patient then PMR is probable. Definite PMR is characterized by probable PMR that has a positive response to corticosteroid therapy[5].

The Hunder criteria for the diagnosis of PMR includes[5]:
• Patient age > 50 years
• Bilateral aching and tenderness for > 1 month of neck or torso, shoulders or upper arms, and hips or thighs
• ESR > 40 mm/hour
• Exclusion of other diagnoses
All the above Hunder criteria must be present to have a diagnosis of definite PMR.
Both of the above criteria have been found to have a sensitivity of >90%.

If the patient also has GCA associated with their PMR, MRI angiography and positron emission tomography (PET) can identify possible vessels involved and monitor the disease course.[5]

There are no validated international guidelines available for the diagnosis and treatment of PMR; however, diagnostic and classification criteria are currently being developed. [13]

The European League Against Rheumatism and American College of Rheumatology have developed classification criteria rather then diagnostic criteria, which must still be validated, and can only be applied to patients in whom new-onset bilateral shoulder pain is not attributable to an anlternative diagnosis: [13]

The European League Against Rheumatism and American College of Rheumatology provisional criteria for classification of polymyalgia Rheumatica (20,21)

Points
Clinical criteria for scoring algorithm

Morning stiffness lasting more than 45 min                                                                                                                          2
Hip pain or restricted range of motion                                                                                                                                  1
Absence of rheumatoid factor and antibody to cyclic citrullinated peptide                                                                           2
Absence of other joint involvement                                                                                                                                      1

Ultrasound criteria for scoring algorithm

At least one shoulder with subdeltoid bursitis, biceps tenosynovitis, or glenohumeral synovitis; and at least one hip with synovitis or trochanteric bursitis                                                                                                                                                             1
Both shoulders with subgeltoid bursitis, biceps tenosynovitis, or glenohumeral synovitis                                                  1

required criteria : age 50 years or older, bilateral shoulder pain, and abnormal ESR, C-reactive protein, or both.
With only clinical criteria, a score of >=4 had a sensitivity of 68 % and a specificity of 78 % for discriminating polymyalgia rheumatic form comparison patients.
With combination of clinical criteria and ultrasound criteria, a score of >= 5 had a sensitivity of 66 % and specific of 81 % for discriminating patients with the disorder from comparison

Table : European League Against Rheumatism and American College of Rheumatology provisional criteria for classification of polymyalgia rheumatic . [20] [21]

Outcome measures

 The health assessment questionnaire, HAQ, is useful in the assessment of functional status in PMR. It correlates well with other measures of the activity of this disease. It shows greater responsiveness to changes than other measures of disease activity. Fixed disabilities may affect its interpretation. Sections of the HAQ related to inflammatory stiffness, such as dressing, grooming and rising, were more responsive to change than other sections, and hence may be more specific for disease activity in PMR. [14] [15]
The Visual Analogue Scale (VAS) for evaluating pain in rheumatology populations. [14]
   

Examination

Shoulder, hip and neck pain but also upper arm pain is usually bilateral and symmetrical. [19] [20] The patient may describe difficulties with daily activities, such as raising their arms above shoulder height – for example brushing their hair or turning over in bed, rising from a bed or chair. [19]
Asking the patient about severity of stiffness in the morning of after periods of rest, [19] compared to the evening may be helpful. Stiffness and pain that lessens over the course of the day can be important in differentiating PMR from other forms of degenerative arthritis, which usually cause pain or stiffness that is worse with activity and worse later in het day. [19] [20]
Pain may irradiate and mild synovitis may be seen in the wrist and knees. [19] [20]
Normal muscle strength, muscle weakness is not a feature of PMR,
Usually no muscle atrophy although this may be difficult to assess due to muscle pain at initial presentation. [19] and unless symptoms are protracted and untreated, disuse atrophy can occur.[19]
Active range of motion may be decreased because of pain. [20]
Tenderness to palpation with a decreased range of motion in the musculature of the proximal hip/leg and/or shoulder.
Constitutional symptoms : the patient may look fatigued , fever may be present, weight loss [19]
     

Systemic Involvement

     The systemic involvement of PMR is stated above in the Characteristics/Clinical Presentations and Co-Morbidities sections.  

Medical Management (current best evidence)

     As stated above in the Medications section, PMR is generally treated with a long course of corticosteroids.  Depending on the facility, the course of treatment will differ.  There is no consensus on the initial dosage and subsequent tapering of corticosteroids. Some suggest an initial dose of 15-20 mg/day of prednisone and then a slow tapering over several weeks or months to find a maintenance dosage.

     If the patient also has GCA, then the initial dose of prednisone is much higher (usually 1 mg/kg of body weight). GCA in the temporal artery is a serious medical condition and could result in blindness if not treated appropriately and quickly.

     Although PMR responds very well to corticosteroids, there is still concern for the adverse effects that occur with long-term steroid use.  This includes diabetes, osteoporosis, hypertension, worsening of cataracts, muscle weakness, and infection.  Patients taking corticosteroids must have their blood sugar, blood pressure, and body weight routinely checked. Due to the increased risk for osteoporosis, vitamin D and calcium supplements should be initiated when the corticosteroids are initiated.

Physical Therapy Management (current best evidence)

     There is currently no evidence for the use of physical therapy in the treatment for PMR.  However, as physical therapists, it is still important to be aware that patients may be referred to you with a primary diagnosis of PMR, or as a co-morbidity.  It is extremely important to be aware of the risk for developing GCA because, as stated above, this is a medical emergency.  See the Co-Morbidities section above for the associated signs/symptoms of GCA.

     If a patient with PMR begins to have increased complaints of muscle pain and stiffness, it is important to ask them if they are still taking their corticosteroids as prescribed. These medications must be tapered appropriately.  Patients may not be fully aware of that and may end their medications prematurely.

      Long-term corticosteroid use also leads to many side effects, such as weight gain, cataracts, mood swings, rounding of the face, difficulty sleeping, glaucoma, diabetes, easy bruising, and hypertension.  Osteoporosis and compression fractures can also be of great concern with these patients.

     Patients may also come into the clinic with a missed diagnosis of PMR.  It is important to keep the signs/symptoms and diagnostic criteria of PMR in mind so that patients get the appropriate treatment they need.

Differential Diagnosis

According to Nothnagl and Leeb, some important differential diagnoses of PMR to keep in mind include:

• Late-onset rheumatoid arthritis (LORA)
• Hypothyroidism
• Fibromyalgia
• Tumor
• Polymyositis/dermatomyositis
• Bursitis/Tendonitis
• Systemic small-vessel vasculitis
• Remitting seronegative symmetric synovitis with pitting edema

Case Reports/ Case Studies

• Polymyalgia rheumatic and exercise: a single case report on one woman [view article in EBSCOhost]
• Isolated lower extremity vasculitis in a patient with polymyalgia rheumatica [view article in EBSCOhost]

Resources

• American College of Rheumatology- http://www.rheumatology.org/practice/clinical/patients/diseases_and_conditions/polymyalgiarheumatica.asp
• National Library of Medicine - http://www.nlm.nih.gov/medlineplus/polymyalgiarheumatica.html
• National Institute of Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse - http://www.niams.nih.gov/Health_Info/Polymyalgia/default.asp
• Arthritis Foundation - http://www.arthritis.org/conditions/diseasecenter/pmr.asp

Recent Related Research (from Pubmed)

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References

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