Polymyalgia Rheumatica

Definition/Description 

Polymyalgia rheumatica (PMR) is a rheumatic inflammatory disease of unknown cause. [1] It causes inflammation of large muscles in the body, with systemic symptoms including malaise, fatigue, fever, and weight loss. [2] In patients with PMR, the synovium and The bursa that lines and lubricates the joint becomes inflamed, causing pain and discomfort. Unlike some other inflammatory diseases, there is no associated permanent damage to the joints or muscles. [2] Polymyalgia rheumatica is also known as muscular rheumatism. [3] PMR is a heterogeneous disease Has a major impact on QOL. [4]

Clinically Relevant Anatomy

PMR is a condition that causes pain in many (multiple) muscles (myalgia) [5]. PMR is characterized by shoulder and hip girdle pain and stiffness with elevated acute phase responses. [6]

Epidemiology/etiology

Although polymyalgia rheumatica occurs worldwide, its incidence is highest in Scandinavian countries and among people of northern European descent. [16] In the United States, the estimated lifetime risk of PMR is 2.43% for women and 1.66% for men. The lowest incidence occurs in Southern European countries such as Italy and Spain. [7]

PMR is most common in people over the age of 50. PMR affects about 7 in 100 people over 50 and about 4 in 10,000 in adults over 60. Prevalence is sex dependent, with a 1:2 ratio of males to females affected. [3] The disease is more common in caucasian. [8]

Some features of PMR suggest that infectious disease exposure may be an environmental factor. The sudden onset of the disease and the periodic appearance of new cases may indicate an infection as the source. Attention has been focused on chlamydia mycoplasma parainfluenza virus or Parvovirus B19 as an infection likely to lead to the development of PMR. Inheritance of the disorder has been suggested due to findings from several genetic studies and patterns in family history. [9] The genes that may cause PMR have not been clearly identified. this Both the HLA-DRB104 and HLA-DRB01 alleles have been found to have a possible association with PMR and GCA, although this remains controversial. [10]

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 circulating Treg cells appeared to be reduced in PMR patients compared with age-matched volunteers. while in On the other hand, there appears to be an increase in TH17 cells. [9]

Characteristics/Clinical Presentation

The onset of PMR can be very sudden. Individuals can usually remember the exact time and date when symptoms began. People often wake up one morning feeling extremely stiff and sore for no apparent reason. Synovitis and bursitis of the shoulder and hip are pain and Symptoms are usually bilateral [10] Other symptoms are found in 40-50% of patients and include: • Stiffness persisting for 30 minutes or more after waking up in the morning or after rest • Weakness • Fatigue • Malaise • Low-grade fever• Sweating• Headache• Weight loss • depression • vision changes

Symptom patterns are characteristic of PMR, although similar symptoms may occur in several other autoimmune infectious endocrine and malignant disorders. It is very important to rule out other diseases.

Differential Diagnosis

There are many conditions that can mimic PMR, such as rheumatoid arthritis (RA) and spondyloarthropathy (SpA). Pain and swelling in distal joints, such as hands, feet and wrists, should raise concern for inflammatory arthritis. Some patients may experience hand swelling and pitting edema. Foot because of tenosynovitis. So-called remitting seronegative symmetric synovitis with pitting edema syndrome [10]

PMR must be differentiated from :

Rheumatological diseases such as:

• Rheumatoid Arthritis
• Spondyloarthropathy
• Crystalline arthritis (calcium pyrophosphate disease and calcium hydroxyapatite disease)
• Remitting seronegative symmetric synovitis with pitting edema syndrome
• Connective tissue diseases
• Vasculitis (giant cell arteritis antineutrophil cytoplasmic antibody-associated vasculitis).
• Inflammatory myopathy (dermatomyositis polymyositis)

Non-inflammatory musculoskeletal disorders such as

• Rotator cuff disease (rotator cuff tear and rotator cuff tendinopathy)
• Adhesive capsulitis
• Degenerative joint disease (degenerative disc disease)
• Fibromyalgia
• Endocrinopathies
• Thyroid diseases
• Disorders of the parathyroid gland
• Infection – viral or bacterial, i.e. sepsis end carditis septic arthritis
• Mycobacterial – eg tuberculosis
• Malignant diseases
• Parkinsonism
• Depression
• Hypovitaminosis D
• Drug-induced myopathy-eg, from statins

Diagnostic Procedures

Polymyalgia rheumatica is a clinical diagnosis. A careful history and physical examination are critical to distinguish this syndrome from other disorders that may present similarly, especially seronegative RA and paraneoplastic syndromes. Laboratory test results are nonspecific and show features Features of systemic inflammation. These include; anemia leukocytosis and elevated inflammatory markers (ESR and CRP) and sometimes elevated liver function tests such as transaminases or alkaline phosphatase. Some clinicians use an erythrocyte sedimentation rate (ESR) above 30 or 40 mm/hr as Diagnostic criteria; however, 6-20% of patients have normal sedimentation [11]. Autoantibodies including rheumatoid factor and cyclic citrullinated peptide antibodies are usually negative and must be considered RA if positive.

Shoulder, hip, neck, and upper arm pain associated with PMR is usually bilateral and symmetrical. Expect tenderness to palpation, but muscle weakness is not a feature of PMR. There is usually mild muscle wasting unless the disease is advanced, and disuse atrophy can happened [12]. Active range of motion is usually reduced by pain. The 24-hour image pattern of PMR typically presents with severe morning stiffness that improves at night and with rest. Pain may radiate, and mild synovitis may develop in the wrists and knees. Associated systemic symptoms may include fatigue, fever, and weight loss.

Radiographs of affected joints in PMR are only useful to rule out other conditions. In a classification study of EULAR/ACR, they found that ultrasonography had high specificity (89%) in distinguishing PMR from other shoulder disorders, but not PMR from RA (70%) [13]

Ultrasound (US) may be valuable in the diagnosis of PMR. Shoulder abnormalities found using US, such as bursitis and tenosynovitis of the long head of the biceps tendon, are more likely to be seen in patients with PMR. However, in the absence of suggestive clinical features, isolated US Abnormalities should not lead to a diagnosis of PMR. [14]

Diagnostic Criteria

Two sets of diagnostic criteria have been created for PMR.

Bird/timber standards[15] include:

• Bilateral shoulder stiffness • Episode duration < 2 weeks • Initial ESR > 40 mm/hr • Stiffness > 60 minutes • Age > 65 years • Depression and/or weight loss • Bilateral upper arm tenderness

If a patient has any 3 or more of the above criteria or more than 1 of the criteria plus a clinical abnormality of the temporal artery, a PMR is likely. Established PMRs are characterized by probable PMRs that respond positively to corticosteroid therapy. Hunder standard [15] include:

• Patient’s age > 50 years • Bilateral pain and tenderness > 1 month in neck or trunk shoulder or upper arm and buttock or thigh • ESR > 40 mm/hr • Exclusion of other diagnoses All of the above Hunder criteria must be present for a diagnosis Confirmed PMR. Both of the above Sensitivity of the criteria was found to be >90%.

The European League Against Rheumatism and the American College of Rheumatology developed classification rather than diagnostic criteria, which still need to be validated and should only be applied in patients with new-onset bilateral shoulder pain not attributable to other causes Diagnosis: [11]

Provisional criteria for the classification of polymyalgia rheumatica by the European League Against Rheumatism and the American College of Rheumatology[16][17]

Clinical criteria for scoring algorithm 2 points – morning stiffness persisting for more than 45 minutes 1 point – hip pain or limited range of motion 2 points – no rheumatoid factor and cyclic citrullinated peptide antibodies 1 point – no other joint involvement Ultrasound scoring algorithm standard 1 point – subdeltoid bursitis, biceps tenosynovitis, or glenohumeral synovitis in at least one shoulder;

Synovitis or trochanteric bursitis on at least one hip

1 point – Subdeltoid bursitis, biceps tenosynovitis, or glenohumeral synovitis in both shoulders

Inclusion criteria using this classification system:

• age 50 years or older
• bilateral shoulder pain
• Abnormal ESR C-reactive protein or both. Based on clinical criteria alone, a score greater than 4 had a sensitivity of 68% and a specificity of 78% for distinguishing patients with the rheumatic type of polymyalgia from the comparison.
  Combining clinical and ultrasound criteria, a score greater than 5 had a sensitivity of 66% and a specificity of 81% and was used to distinguish patients with the condition from comparisons

Treatment

PMR is usually treated with long-term corticosteroids. There is no consensus on the initial dose and subsequent titration of corticosteroid doses. Some suggest an initial dose of 15-20 mg/day prednisone, followed by a slow taper over weeks or months to find a maintenance dose dose. Although PMR responds very well to corticosteroids, there are concerns about adverse effects of long-term steroid use. This includes diabetes, osteoporosis, high blood pressure, worsening cataracts, muscle weakness, and infections. Patients taking corticosteroids must Regularly check blood sugar, blood pressure and weight. Because of the increased risk of osteoporosis, vitamin D and calcium supplementation should be initiated when corticosteroids are initiated. [18]

Complete clinical remission may take up to 5 years. [19]

Physical Therapy Management 

There is currently no evidence that physical therapy can be used to treat people with PMR. However, it is still important to note that patients may still be referred to you with their initial diagnosis of PMR or with PMR as a comorbidity. Physiotherapy can be a valuable An integral part of a treatment corps for this patient group to reduce the risk of early functional impairment and severe disability. [20] In the treatment of PMR, a combination of exercise therapy and education is recommended.