When polymyalgia rheumatica (PMR) occurs, the body's immune system attacks its own connective tissues, causing the tissue of the affected joints and occasionally arteries to become inflamed.
The disease can last for up to 5 years but usually less and is responsive to low to moderate doses of prednisone (steroid).
PMR affects around 59 out of 100,000 people over the age of 50 each year and is most often seen in Caucasian women. It is the most common inflammatory disease to affect the elderly and is rarely seen in those who are under age 50. On average, the disease tends to develop around the age of 70.
The inflammation caused by PMR can lead to generalized aching, stiffness, and flu-like symptoms in both sides of the body. The most commonly affected joints are the shoulders or shoulder girdle and the hips or hip girdle. Arteries that can be affected include some of the major branches of the heart.
Causes and risk factors
A frequent symptom of polymyalgia rheumatica is stiffness in the neck.
While the causes of PMR are not well understood, there are many theories as to its cause.
It is suggested that the condition is the result of inflammation in the joints and the sacs surrounding the joints known as the bursae. This inflammation may lead to referred pain in other parts of the body. For example, if the shoulder and hip joints are affected, pain may be experienced in the upper arms and thighs.
While there is no definitive evidence, PMR could also result from an infection. Additional research is needed to determine the cause and risk factors associated with PMR.
Tiredness, weakness, and sleep disturbances may be symptoms that people who are diagnosed with PMR experience.
People with PMR may experience a rapid onset of symptoms, which develop over a few days or weeks. In some cases, the symptoms occur overnight, and the pain and stiffness are severe.
One symptom is pain that can be worse in the morning with improvement throughout the day. This pain may make it difficult for people to get dressed at the start of the day. Raising their arms above the head to comb their hair can be challenging.
Another frequent symptom people have is stiffness in at least two areas. Commonly affected areas include the buttocks, hips, neck, thighs, upper arms, and shoulders.
Other symptoms often experienced by people diagnosed with PMR include:
- difficulty getting up from a seated position
- pain that worsens with inactivity
- joint and muscle aching
- difficulty raising the arms above the shoulders
- decreased appetite
- weight loss
- sleep disturbances
Although uncommon, swelling of the hands, forearms, and feet may occur. The symptoms of carpal tunnel syndrome, which include tingling and weakness in the hand, wrist, and arm, may also occur.
Around 5-15 percent of those with PMR will go on to develop a condition called giant cell arteritis (GCA), also referred to as temporal arteritis (TA). Nearly half of those who are first diagnosed with GCA also have symptoms consistent with PMR.
GCA causes inflammation of the blood vessels, referred to as vasculitis, most commonly affecting the arteries within the scalp and the head. If untreated, GCA can lead to vision loss.
Symptoms of GCA require medical attention and include the following:
- one-sided headaches, especially around the temples
- scalp tenderness
- visual changes, such as temporary blurring, double vision, or blindness
- jaw pain when eating
- loss of appetite
- flu-like symptoms
- facial, tongue, or throat pain
While diagnosing PMR can be difficult, there are procedures that help when trying to identify the disease.
As well as doing a physical examination, a doctor will evaluate a person's medical history and symptoms as part of the diagnostic process.
A blood test may be recommended by a doctor to diagnose PMR.
They may also recommend certain tests to help them rule out similar medical conditions, such as:
- rheumatoid arthritis
- hypothyroid disease
- multiple myeloma or other cancers
A doctor may recommend various blood tests during the diagnosis process. These might include the following tests:
- Anticyclic citrullinated peptide (anti-CCP): This detects an antibody found in people with rheumatoid arthritis.
- Antinuclear antibody (ANA): A test that may indicate the presence of lupus, Sjogren's, or other autoimmune diseases.
- Complete blood count (CBC): This evaluates white blood cell, red blood cell, and platelet levels.
- C-reactive protein (CRP): This can identify the presence of inflammation.
- Erythrocyte sedimentation rate (ESR): This is also referred to as a sed rate and detects the presence of inflammation.
- Rheumatoid factor (RF): A test used to diagnose rheumatoid arthritis.
- Thyroid stimulating hormone: A blood test to evaluate how well the thyroid is working.
- Creatinine kinase (CK): Another blood test to look for muscle damage.
In cases of PMR, findings might include an elevation in C-reactive protein and erythrocyte sedimentation rates, which indicate an inflammatory response.
Doctors may recommend other testing, such as imaging studies. If GCA is considered a cause of symptoms, a biopsy of the temporal artery is arranged, as soon as possible.
Additional testing may be recommended on an individual basis and will be discussed by the healthcare team.
Treatment for PMR can begin as soon as a diagnosis is made. The goal of PMR treatment is to reduce the symptoms of pain, stiffness, inflammation, aching, fever, and tiredness with the use of certain anti-inflammatory medications and exercise.
Medications used to treat PMR are referred to as anti-inflammatory drugs and include corticosteroids like prednisone.
During steroid treatment, the effect on inflammation is monitored with blood tests like ESR and C-reactive protein levels. Often, those being treated for PMR feel rapid improvement with steroid therapy.
In rare cases, adding medications, such as methotrexate or azathioprine, may be recommended to make it easier to reduce the steroid dose gradually. The goal of treatment is to maintain symptom relief with the lowest dose of steroids as possible.
In very mild cases, non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, may be sufficient.
A regular exercise program with periods of rest may be recommended as part of the treatment plan.
The goal of exercise is to maintain joint flexibility, strength, and function. Depending on a person's overall health and fitness status, it may be recommended that walking, stationary bicycle, and pool exercises are added to a person's fitness plan.
While PMR is a treatable disease, complications may occur as a result of long-term steroid use. These complications include:
- elevated blood sugar levels
- weight gain
- brittle bones
- skin thinning
- high blood pressure
- anxiety or agitation
If someone with PMR develops GCA, this can lead to complications, such as:
- blood vessel narrowing
- aneurysm formation
It is vital that those diagnosed with PMR report the onset of any new headaches, scalp tenderness, visual changes, and jaw pain immediately, so that they can be evaluated and treated for GCA.