History

History

Polymyalgia rheumatica (PMR) was first described by Bruce (1) in 1888 when he reported on five senior patients with a proximal muscular syndrome he called "senile rheumatic gout."

The syndrome next appeared under the name "humeroscapular periarthrosis" in 1945 and later "anarthritic rheumatoid arthritis." This later term was coined by Bagratuni (2) because he felt that such patients had a forme fruste of rheumatoid arthritis (RA). Two of the 50 patients he reported went on to develop RA and 8 others had transient swelling of various joints. He felt that the term anarthritic rheumatoid arthritis was more appropriate than "polymyalgia rheumatica" coined by Barber (3) in 1957. Finally, Healey (4) has furthered the concept of PMR as a systemic articular disease by describing variant forms of PMR which he calls benign synovitis and will be discussed below.

Epidemiology

The annual incidence of PMR among patients over the age of 50 is 20-50/100,000.

Most cases are over the age of 60 but cases have been reported to occur in individuals in their mid 40's. Caucasians, especially those of Northern European descent are at the greatest risk. In addition, twice as many women as men are affected. In some selected populations, the prevalence of PMR may be as high as 500/100,000 (5).

Recently, HLA typing has identified the DR4 molecule as a risk factor for the development of PMR and temporal arteritis (TA) albeit a different subtype than that placing individuals at risk for RA.

Pathophysiology

PMR is a systemic inflammatory illness that does not actually involve the muscles in spite of the name.

It is actually a synovitis of the large proximal joints although more distal joints can also be involved. Bone scans, arthroscopy, magnetic resonance scans (MRI), and synovial biopsy have all documented the synovial nature of the illness. Open biopsy of the shoulder in patients with PMR has revealed the wide spread involvement of the periarticular synovial tissues such as bursa as well as the joint (6). MRI scans document that the bursae about the shoulder are also frequently involved (7). These data suggest a mechanism for some of the mechanical type symptoms these patients can manifest.

Clinical features

The typical symptoms of PMR include profound AM stiffness so much so that patients have to roll themselves out of the bed.

There is night pain and stiffness and gelling with inactivity. Most of the symptoms occur in a proximal distribution. Up to 20% of patients felt to have typical PMR have synovitis of other joints especially the knee. There are probable variants of PMR that look more like rheumatoid arthritis. Systemic symptoms also occur and include anorexia, weight loss, fever, and fatigue. The disease often begins acutely with the patient able to remember the day or week the symptoms began.

Laboratory features according to Chuang et al include (5):

The natural history of PMR has been documented by several report of the disease in the precorticosteroid era notably Gordon (8). He described the course of PMR in 8 patients and noted 2 phases. The first phase consisted of intense stiffness that usually peaked early in the illness and would partially resolve. The second phase was one of relatively mild symptom requiring little medication and this would completely resolve in an average of 2 years. Most authors report that the mean length of PMR is around 2 years although it appears that there is a large group that is off corticosteroids by 2 years and a smaller group that need therapy for a more prolonged period.

Clinically pure PMR (i.e. no symtoms of TA) will occasionally be complicated by the development of TA. The numbers indicate about 10% of those presenting initially with only PMR will develop TA (5). The converse is not true as upwards of 50% of people with TA will have coexisting PMR. Patients with clinically pure PMR may have a positive temporal artery biopsy for arteritis but several studies addressing the issue have indicated that this is not predictive for progression to TA.

Treatment

The treatment of PMR entails patient education, medications, physical therapy, and prevention of osteoporosis.

Patients with milder disease may respond to NSAIDs alone. Chuang et al were able to treat 30 of 93 PMR patients with NSAIDs and found that these were usually patients with lower initial ESR and milder symptoms (5). Often felt to be more benign than corticosteroids, 3 of the 30 developed GI bleeds (10%).

Most patients will need corticosteroids. The usually dose is 10-20 mg of prednisone in a single daily dose. Most will do well on less than 15 mg/day. If the patient has continued AM stiffness of 15 mg, I like to break the dose into 10 mg in the AM and 5 mg at night rather than increasing the total dose. The night time dose is the first to be tapered. Most patients respond within 24-48 hours often with dramatic relief. The response is diagnostic of the illness and may be helpful in sorting out other possibilities.

The initial dose at which symptoms are controlled is continued for 4-6 weeks and then a slow taper is begun. The prednisone should tapered 1 mg at a time and no faster than 3 mg per month. We are able to taper the corticosteroids because we often over treat initially and because the natural course of the disease causes the symptoms to lessen. It is important to remember that corticosteroids do not cure the illness but only suppress the symptoms until nature takes its course. We often find a level at which the prednisone can not be lowered further and the dose is maintained several weeks to months at that level but the physician and the patient should always be trying to push the dose lower.

Relapses are common and rather than make large jumps in the dose, most patients need only resume their previous dose at which they were comfortable. Remember that most patients will need an average of 2 years of treatment.

An interesting alternative to the usual method of corticosteroid dosing was published in 1991 by Dasgupta et al (9). They treated 16 patients with 120 mg of depomedrol q 3 weeks x 12 then 120 mg q month x 3 and then tapered by 30 mg q 3 months. This resulted in a significantly lower cumulative dose of corticosteroids and no evidence of hypothalamus-pituitary axis suppression as measured at 3 months. At one year, 3 patients developed minor bruising as the only reported side effects and 3 patients dropped out of the protocol. Other agents such as azathioprine, methotrexate, dapsone, and hydroxychloroquine have been used as steroid sparing agents in selected patients.

Finally, physical therapy is useful for treating shoulder capsulitis and rotator cuff weakness that often develops and I have found that patients residual "stiffness" is more often than not mechanical rather than inflammatory in nature. Prednisone can cause a myopathy and a fibromyalgia-like illness that seems to be preventable by gentle aerobic conditioning. Weight bearing exercise also helps prevent osteoporosis. It is important to maintain adequate calcium (1000-1500 mg/day) and vitamin D (400-800u/day). Some authors advocate assessing all patients who will be treated with more than 7 mg of prednisone for more than 3 months with bone densitometry and repeating in 3-6 months as not everybody on corticosteroids will develop osteoporosis and those with preexisting osteoporosis will need close scrutiny from the outset alternatives to standard therapy considered. The American College of Rheumatology has recently developed guidelines for steroid-induced osteoporosis and is available at www.rheumatology.org.

References

1) Bruce, W.: Senile rheumatic gout. Br. Med. J . 2:811, 1888.

2) Bagratuni, L.: Prognosis in anarthritic rheumatoid syndrome. Br. Med. J. 1:513, 1963.

3) Barber, H.S.: Myalgic syndrome with constitutional effects: polymyalgia rheumatica. Ann. Rheum. Dis. 16:230, 1957.

4) Healey LA: The overlap of rheumatoid arthritis and polymyalgia rheumatica in older patients. Mediguide to Inflammatory Diseases 1989;8:Issue 1.

5) Chuang, T.Y., Hunder, G.G., Ilstrup, D.M., and Kurland, T.: Polymyalgia rheumatica: a 10 year epidemiologic and clinical study. Ann. Int. Med. 97:672, 1982.

6) Chou CT, Schumacher HR: CLinical and pathologic studies of synovitis in polymyalgia rheumatica. Arthritis Rheum. 27:1107-1117, 1984

7) Cantini F, Salvarani C, Macchioni P, et al: Shoulders and hips: magnetic resonance imagining in polymyalgia rheumatica. Arthritis Rheum. 39(suppl):S201, 1996.

8) Gordon, I.: Polymyalgia rheumatica. Quart. J. Med. 29:273, 1960.

Other references of interest

9) Behn, A.R., Perera, T., and Myles, A.B.: Polymyalgia rheumatica and corticosteroids: how much for how long? Ann. Rheum. Dis. 42:374, 1983.

10) Healey, L.A., and Wilske, K.R.: The Systemic Manifestations of Temporal Arteritis. New York, Grune & Stratton, 1978.

11) Spiera, H., and Davison, S.: Treatment of polymyalgia rheumatica. Arthritis Rheum. 25:120, 1982.

12) Delecoeuillerie, G., Joly, P., Cohen De Lara, A., and Paolaggi, J.B.: Polymyalgia rheumatica and temporal arteritis: a retrospective analysis of prognostic features and corticosteroid regimens. Ann. Rheum. Dis. 47:733, 1988.

13) Jones, J.G., and Hazleman, B.L.: Prognosis and management of polymyalgia rheumatica. Ann. Rheum. Dis. 40:1, 1981.

14) Davidson, S., Speira, H., and Plotz, C.M.: Polymyalgia rheumatica. Arthritis Rheum. 9:18, 1966.

15) Hunder, G.G., Disney, T. F., and Ward, L.E.: Polymyalgia rheumatica. Mayo Clin. Proc. 44:849, 1969.

16) Lundberg, I., and Hedfors, E.: Restricted dose and duration of corticosteroid treatment in patients with polymyalgia rheumatica and temporal arteritis. J. Rheumatol. 17:1340, 1990.

17) Speira, H., and Davidson, S.: Long-term follow-up of polymyalgia rheumatica. Mt. Sinai J. Med. 45:225, 1978.

18) Kyle, V., and Hazleman, B.L.: Treatment of polymyalgia rheumatica and giant cell arteritis. I. steroid regimens in the first two months. Ann. Rheum. Dis. 48:658, 1989.

19) Ayoub, W.T., Franklin, C.M., and Torretti, D.: Polymyalgia rheumatica: duration of therapy and long-term outcome. Am J. Med. 79:309, 1985.

20) Kyle, V., and Hazelman, B.L.: Stopping steroids in polymyalgia rheumatica and giant cell arteritis. Br. Med. J. 300:344, 1990.

21) Dasgupta, B., Gray, J., Fernandez, L., and Olliff, C.: The treatment of polymyalgia rheumatica with injections of depot methylprednisone. Ann. Rheum. Dis. 50:942, 1991.

22) Weissenbach, R., Nobilliot, A., Freneaux, R., and Coste, F.: Pseudo-polyarthrite rhizomelique. Sem. Hop. Paris. 39:2073, 1963.

23) de Seze, S., Lequesne, M., and Veber, A.: Le rheumatisme inflammatorie des ceintures ou pseudo-polyarthrite rhizomelique avec 45 observations. Sem. Hop. Paris. 41:711, 1965.

24) Doury, P., Pattin, S., Eulry, F., and Thabaut, A.: The use of dapsone in the treatment of giant cell arthritis and polymyalgia rheumatica. Arthritis Rheum. 26: 698, 1983.

25) Fowler, B., Dideriksen, K., Stentoft, J., and Jensen M.K.: Dapsone in temporal arteritis and polymyalgia rheumatica. J. Rheumatol. 15:879, 1988.

26) De Silva, M., and Hazleman, B.L.: Azathioprine in giant cell arteritis/polymyalgia rheumatica: a double-blind study. Ann Rheum. Dis. 45:136, 1986.

27) Settas, L., Dimitriadis, G., Sfetsios, T., Disa, E., Souliou, E., and Tourkantonis, A.: Methotrexate versus azathioprine in polymyalgia rheumatica-giant cell arteritis: a double blind, cross over trial. Arthritis Rheum. 34(supplement): S72, 1991.

28) Krall, P.A., Mazanec, D.J., and Wilke, W.: Methotrexate for corticosteroid-resistant polymyalgia rheumatica and giant cell arteritis. Cleve. Clin. J. Med. 56:253, 1989.

Surgery for arthritis at the University of Washington, Department of Orthopaedics and Sports Medicine, Seattle, Washington