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Woman with achy shoulder muscles

My patient’s medical history notes PMR. What is it?

June 7, 2024
Sometimes, muscle soreness from exercise can be mistaken for polymyalgia rheumatica (PMR), which is an inflammatory autoimmune disorder. This can inhibit mobility and pose oral hygiene challenges for patients.

Anyone who has overworked themselves when they exercise knows how uncomfortable achy muscles can be, but what they may not know is that this soreness is often caused by the buildup of lactic acid. Muscle soreness is especially prevalent during high-intensity exercises, but it usually subsides within a couple hours or several days, at worst. However, some people are sore for a prolonged period of time, which differs from the slow onset of joint-related arthritic pain.

Muscle soreness or something more? It might be PMR

But what happens when someone experiences a rapid onset of muscle aches that mimic arthritis, yet lacks other arthritic symptoms? A rheumatologist or primary care physician can explore possible causes. One possible culprit is polymyalgia rheumatica (PMR), which is an inflammatory autoimmune disorder that causes muscle pain and stiffness on both sides of the body-especially in the neck, shoulders, upper back, thighs, buttocks, and hips. It can also cause fatigue, weight loss, poor appetite, and even flu-like symptoms. Although the cause is unknown, genetic and environmental factors contribute to the onset of PMR.

Similar to arthritis, those with PMR experience pain and stiffness that is usually worse in the morning or after periods of inactivity. As a result, patients will often try to avoid using the affected muscles, which can lead to muscle weakness. Patients may also suffer from poor sleep, problems getting in and out of a car or up from chairs, and difficulty dressing or bathing. For dental professionals, patients may have difficulty getting up from the operatory chair and maintaining oral hygiene routines at home.

The difference between PMR and fibromyalgia

PMR and fibromyalgia are often confused since both involve muscle pain that may persist on both sides of the body. The primary difference is that PMR is inflammatory while fibromyalgia pertains to the abnormal sensory processing of the central nervous system, making patients extremely sensitive to pain. Fibromyalgia causes tender points on the body, headaches, and irritable bowel symptoms and is treated with exercise, analgesic medications, and antidepressants. Conversely, treatment for PMR focuses on reducing inflammation. Fibromyalgia can occur at any age, but PMR is typically present in Caucasian females over the age of 50 and can last several years. 2

Treating and diagnosing PMR

After a PMR diagnosis, clinicians will review a patient's symptoms and perform a complete medical history report, including information about family members and any other autoimmune diseases. Routine blood tests can be performed with specialized tests for inflammation markers to rule out any other underlying issues. These include but are not limited to:

  • Anticyclic citrullinated peptide (anti-CCP): rheumatoid arthritis marker

  • Antinuclear antibody (ANA): autoimmune marker

  • Complete blood count (CBC): overall health marker

  • C-reactive protein (CRP): inflammation marker

  • Erythrocyte sedimentation rate (ESR, also called sed rate): inflammatory, cancer or blood disorder marker

  • Rheumatoid factor (RF): rheumatoid arthritis or Sjogren's marker 3,4

To treat PMR, introduce a regimen of low dose corticosteroid along with increased exercise. The most common corticosteroid prescribed is prednisone. There is debate as to whether nonsteroidal anti-inflammatories (NSAIDS) such ibuprofen or naproxen help PMR patients, but in either case, symptoms typically subside rapidly once patients start taking medication. Usually, patients experience relief with a low dose prednisone (10-15 mg) within days of beginning treatment. If symptoms improve after a few weeks of treatment, patients are advised to gradually taper their dose over several months. Some patients are on corticosteroids for several years if symptoms continue or recur. Side effects of corticosteroids include increased appetite, weight gain, mood changes, blurred vision, resistance to infection, and more.4

Methotrexate, azathioprine, and other immunosuppressive therapies are occasionally prescribed to patients with corticosteroid intolerance.6 A new steroid-free biologic medication has recently been approved for treatment as well. Kevzara (generic: sarillymab) is an injectable medication that is an interleukin-6 receptor blocker. These blockers work by suppressing abnormal activity in the immune system that causes the body to attack healthy tissue, such as in rheumatoid arthritis (RA). In clinical trials submitted to the FDA for approval, Kevzara was almost three times more effective in helping patients relieve PMR or RA symptoms as opposed to a placebo.7 However, long-term results are not available. Calcium and vitamin D supplementation is also important when taking any of the PMR medications.

In addition to medication, exercise and proper rest are important in managing PMR. Regular exercise is essential for maintaining joint flexibility, muscle strength, and function. In addition to physical therapy, walking, bike riding, and swimming/water aerobics are excellent for PMR patients. As always, rest allows the body to recover from exercise or other daily activities.

Although there is no conclusive relationship between diet and PMR, patients reported feeling better while maintaining a gluten-free or paleo diet - both of which restrict the number of inflammatory foods (such as wheat or sugar) being consumed.

Conclusion

PMR is usually self-limiting; most patients experience the disease following treatment for approximately 2-3 years with an excellent prognosis. But without treatment, overall quality of life can be severely impaired, and if steroid treatment is tapered too quickly, relapses can occur. Relapses are most common during the first 18 months of treatment, or within 12 months of corticosteroid cessation.8

Approximately 15% of people with this disorder develop a potentially dangerous condition called giant cell arteritis (GCA), also known as temporal arteritis.1 GCA is an inflammatory disease that causes a narrowing or blockage of the blood vessels in the scalp, neck, and arms. This, consequently, interrupts blood flow. PMR patients should also be monitored for signs of GCA.

For dental professionals, having mobility questions on the practice's medical history as well as observing the patient for mobility issues when entering/leaving the operatory is essential. Since most PMR patients may have difficulty getting up from a seated position, observe how they move around the office.

Although most PMR patients have difficulty using the larger muscles, some may also exhibit pain and stiffness in their wrists or hands, making homecare difficult. Utilizing power brushes, oral irrigators, inter-dental cleaners, and toothpaste in pump dispensers can help maintain a PMR patient's oral hygiene. During longer appointments, mouth props have been found to be helpful. PMR patients should be on a 3- to 4-month recare schedule and questioned regarding corticosteroid or other side effects from medication.

Fifty out of 100,000 people in the United States are diagnosed with polymyalgia rheumatica each year.9 In fact, there may be a patient in your practice who either has the disorder or knows someone who does. Understanding this disease and how to properly treat it can make all the difference in your patients' lives and wellbeing.

References

1. Arthritis Foundation. Polymyalgia Rheumatica. https://www.athritis.org/diseases/polymyalgia-rheumatica

2 American College of Rheumatology. Polymyalgia Rheumatica. https://rheumatology.org/patients/polymyalgia-rheumatica

3. https://www.arthritis.org/diseases/polymyalgia-rheumatica#

4. National Library of Medicine. Lab Tests. https://medlineplus.gov/lab-tests/

5. Cleveland Clinic. Corticosteroids. Reviewed January 20, 2020. https://my.clevelandclinic.org/health/drugs/4812-corticosteroids

6. Mayo Clinic. Polymyalgia Rheumatica: Symptoms & Causes. June 16, 2022. https://www.mayoclinic.org/diseases-conditions/polymyalgia-rheumatica/symptoms-causes/syc-20376539

7. Everyday Health. FDA Approves Steroid-Free Treatment for Polymyalgia Rheumatica. Fact Checked March 16, 2023. https://www.everydayhealth.com/rheumatic-diseases/fda-approves-steroid-free-treatment-for-polymyalgia-rheumatica/

8. US Pharmacist. Polymyalgia Rheumatica: A Severe Self-Limiting Disease. June 20, 2012. https://www.uspharmacist.com/article/polymyalgia-rheumatica-a-severe-self-limiting-disease

9. Vasculitis Foundation. Polymyalgia Rheumatica. Updated February 5, 2024. https://www.vasculitisfoundation.org/education/forms/polymyalgia-rheumatica/#1545067703667-338449ab-a1cb

Ann-Marie DePalma, MEd, RDH, CDA, FAADH, FADIA, FADHA, presents continuing education programs for dental team members and is a published author in dental hygiene/dental publications and textbooks. She is a Massachusetts College of Pharmacy and Health Sciences Esther Wilkins Distinguished Alumni Recipient. She is a member of numerous professional organizations and volunteers locally.