Definition and Overview
Polymyalgia Rheumatica (PMR) is a kind of rheumatoid disorder characterized by mild to severe pain in the shoulders, hip, and neck. It may develop gradually and slowly or occur suddenly (literally overnight). The muscle stiffness, one of its prominent symptoms, usually happens in the morning, as soon as waking up, and lasts for at least 30 minutes.
Like many of the inflammatory diseases such as arthritis, there is no known cure for polymyalgia rheumatica, but the symptoms may be kept at bay through a combination of treatments. The goal is to significantly reduce the recurrence and prevent the symptoms from getting worse.
This condition is often confused with fibromyalgia since both of them cause muscle pain (hence, myalgia). However, they are different. Aside from the fact that PMR attacks specific parts of the body, it is also a type of inflammation of the muscles. A person with fibromyalgia, meanwhile, develops sensitivity to musculoskeletal pain especially in trigger or tender points. A person diagnosed with fibro should have at least 11 of these tender points.
PMR is also often related to giant cell arteritis, also referred to as temporal arteritis. It is an inflammation disorder affecting the scalp, arm, and neck arteries.
Of the 100,000 people who are more than 50 years old in the United States, at least 700 will be diagnosed with PMR.
Causes of Condition
The exact cause of polymyalgia rheumatica is unknown, although some studies have cited the following:
Age – This disease is extremely rare among people under 50 years old, although it has the probability to occur quite rapidly as they age. It is often diagnosed on those who are more than 65 years old (average age is 70).
Giant cell arteritis – Health experts cannot fully explain the connection between giant cell arteritis and PMR, but they tend to happen at the same time, or one increases the risk of the other.
Genetics and race – In a study of Marco Cimmino published in the Annals of Rheumatic Diseases, genetics has long been believed to be a reason for PMR because of its prevalence in certain regions of the world. It is more common in Northern Europe than in Southern Europe. While PMR is also high in the United States, many of the patients are found in Minnesota whose ancestors can be traced to Scandinavia. Meanwhile, those with African-American or African lineage are less likely to develop the disorder.
It is also associated with HLA-DR4, a gene of the immune system and is found in more than 65% of European descent.
Gender – Women are at a higher risk of developing PMR than men, more so if they are of Caucasian descent. However, men diagnosed with giant cell arteritis have a higher chance of getting blind if left untreated.
Environmental exposure – Since PMR is an infection affecting the joints and muscles, some believe that a virus may also trigger the symptoms and eventually cause the disorder. However, it’s not clear what specific virus can lead to it.
Abnormal immune response – The immune system is in charge of protecting the body from different threats such as viruses and bacteria. When these threats invade the body, the immune cells surround, eliminate, or kill them. However, sometimes they respond abnormally wherein they attack the tissues, leading to inflammation.
- Stiffness especially in the morning
- Muscle pain affecting the neck, shoulders, and hip
- Difficulty in moving
- Sleep disruption
- Presence of giant cell arteritis
- Joint aches especially in the wrists and hands
- Pain extending in the buttocks and thighs
- Fatigue or lethargy
- Sudden or unintended weight loss
- Depressive mood
- Low-grade fever
- Profuse sweating at night
- Swelling of the joints and tendons
- Tenderness of the inflamed tissues
- Muscle stiffness after being in the same position (like sitting) for a long period
Who to See and Treatments Available
A person who is suspected or has been diagnosed with PMR should work closely with a rheumatoid specialist or a rheumatologist, a medical doctor/internist who is responsible for diagnosing, treating, and managing rheumatic-related diseases.
To make a diagnosis, the doctor may perform a comprehensive physical examination including identifying any tender points or sites of muscular pain especially in the hip, shoulders, and neck. The joints in the hands, knees, and neck may also be slightly swollen. Body temperature may also be checked while a review of symptoms, family history, and other illnesses will be conducted. If a person has already been diagnosed with giant cell arteritis, most likely, the doctor will suspect PMR and consider it when conducting the physical examination.
The doctor may also request a blood test to determine the ESR (erythrocyte sedimentation rate), which confirms if there is inflammation in the body although it cannot pinpoint where or the exact cause. Other tests will measure liver function and C-reactive protein.
As for its treatment, the first option is to prescribe a medication, preferably corticosteroids, which reduce inflammation, to immediately relieve the pain and muscle stiffness. Because of the possible serious side effects of this drug such as osteoporosis, a patient is given only a very low dose of around 10 mg. The symptoms should subside after one intake or within 3 weeks. Otherwise, the cause of the pain may not be PMR.
The dosage should also be tapered or reduced until the doctor finds the ideal one that prevents the symptoms and almost eliminates the side effects.
Meanwhile, those who have been diagnosed with hypertension, diabetes, glaucoma, and a peptic ulcer may receive steroids through an injection.
NSAIDs (non-steroidal anti-inflammatory drugs) are also usually given for temporary pain relief, but some doctors think they don’t work for PMR.
The doctor may also advise:
- A complete lifestyle change including avoiding smoking and excessive drinking of alcohol
- Increase in physical activity as being in the same position such as sitting for a prolonged period usually triggers muscle stiffness
- Exercise, especially with weights
Diet rich in vitamin D and calcium (calcium intake may have to be increased if the patient is taking corticosteroids since the drug counters the effects of the mineral)
Hellmann DB. Giant Cell Arteritis, Polymyalgia Rheumatica, and Takayasu's Arteritis. In: Firestein GS, Budd RC, Gabriel SE, et al, eds. Kelley's Textbook of Rheumatology. 9th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 88
- American College of Rheumatology