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Polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) frequently affect
the same types of people. The diseases may occur independently or in the same
patient, either together or at different times.
Who is affected by PMR and GCA?
People over 50 years old are typically affected with PMR and GCA. The average
age of patients is 70. One-third of patients with GCA also have PMR.
These diseases are more common among women, and there is a higher incidence
among Caucasians than any other ethnic group.
What causes PMR and GCA?
The exact cause of these illnesses is unknown.
What is giant cell arteritis (GCA)?
Giant cell arteritis causes inflammation that damages the arteries (blood
vessels that carry blood and nutrients from the heart to tissues in the body).
The large and medium-sized arteries are affected.
Because some of the affected arteries provide blood to the cranium (head),
including the temples, the condition may also be called cranial or temporal
arteritis.
What are the symptoms of GCA? How often do they occur?
- Atypical severe headaches are the most common symptom and occur
in over 80 percent of patients
- Scalp tenderness, fatigue, fevers and a general sense of
illness is common in about 50 percent of patients
- Jaw or facial soreness, especially with chewing, occur in about
50 percent of patients
- Vision changes or distorted vision caused by decreased blood
flow occur in 15 to 50 percent of patients; blindness occurs in 5 to 15
percent of patients
- Stroke may occur in less than 5 percent of patients and is
caused by decreased blood flow
- The large blood vessels may become narrowed or enlarged
(aneurysm). See figure below.
If narrowing occurs in the blood vessels
leading to the arms or legs, patients may notice fatigue or aching in the
limbs, due to a reduced blood supply. Weak or absent pulses may be noticed
by the doctor. These symptoms occur in 15 to 20 percent of patients.
- Other symptoms may include fever, weight loss, night sweats,
depression, fatigue and a general feeling of being ill
A blood vessel can become inflamed and narrowed or segments of a blood
vessel can weaken and stretch, resulting in an aneurysm.
When aneurysms occur, they are usually present in the aorta, the body's
largest vessel that carries blood from the heart.
When blood vessels become narrowed, there is restricted
blood flow. If the blood vessel is completely occluded (blocked), there is
no blood flow through that segment.
How is GCA diagnosed?
The diagnosis of GCA is based on the presence of previously noted symptoms
and/or the finding of abnormal blood flow in the arms, legs, or aorta;
tenderness of the scalp or temples; and visual abnormalities.
Once the diagnosis has been made, treatment should be started as soon as
possible.
If the diagnosis is suspected, but less convincing features are present, a
temporal artery biopsy may confirm the diagnosis. The biopsy is taken from a
part of the artery located in the hairline, in front of the ear. The biopsy is
helpful in most cases, but in some individuals it may be negative or normal,
even though the disease is present.
What is polymyalgia rheumatica (PMR)?
Polymyalgia literally means "many muscle pains." Rheumatica means
"changing" or "in flux."
What are the symptoms of PMR?
Pain or aching is usually felt in the large muscle groups, especially around the
shoulders and hips.
Other symptoms may include:
- Stiffness, especially in the morning and after resting
- Weakness
- Fatigue
- Generally feeling ill
- Mild fevers (occasionally)
- Weight loss
Can other problems be confused with PMR?
Yes. Some other illnesses that may be confused with PMR include:
- Rheumatoid arthritis
- Infections
- Inflammation of blood vessels (vasculitis)
- Metabolic (chemical and hormone) abnormalities
- A variety of muscle diseases
- Cancer and many other diseases
Since there are so many illnesses that mimic PMR, how is it diagnosed?
PMR is diagnosed after:
- Careful evaluation of a person's medical history with an
emphasis on the presence of pain, aching and stiffness in the shoulder,
pelvic and hip regions.
- A complete physical exam. During the exam, the presence of
common PMR features and the effects of other illnesses are evaluated.
- Excluding the possibility of other illnesses. Blood test
results may show distinct abnormalities typical of other diseases that would
suggest different diagnoses.
- Evaluating the results of blood tests.
- Quick recovery and disappearance of symptoms after treatment
with low-dose corticosteroids.
How are PMR and GCA treated?
There is no known cure for PMR and GCA, but these diseases can be treated and
controlled.
Corticosteroid treatment helps rapidly relieve symptoms of both PMR and GCA.
Treatment with corticosteroids is mandatory for GCA to prevent serious vascular
complications, such as blindness. Low doses of corticosteroids are often
successful in treating PMR. Higher doses are often required to control GCA.
The excellent response to treatment is so uniform that the lack of dramatic
improvement, within days, would make the diagnosis of GCA or PMR doubtful.
Corticosteroids (or "steroids") are man-made drugs that closely
resemble cortisol, a hormone that the adrenal glands produce naturally. Some
corticosteroid medications include cortisone, prednisone and methylprednisolone.
Prednisone is the most commonly used steroid to treat certain rheumatic
diseases.
Steroids reduce the numbers of inflammatory cells and chemicals that cause
these illnesses. Consequently, steroids minimize tissue damage. Steroids also
reduce the normal activity of the immune system by affecting the protective
functions of white blood cells.
The decision to prescribe steroids is always made on an individual basis.
Your doctor will consider your age, presence of other illnesses and medications
you are taking. Your doctor will also make sure you understand the potential
benefits and risks of steroids before you start taking them.
You will have frequent blood tests while taking steroids to monitor possible
side effects and to evaluate the effectiveness of therapy. These blood tests can
usually detect problems before you are aware of any symptoms. Your doctor will
also frequently evaluate your heart and lung function and blood sugar level,
which may be increased secondary to steroids.
While taking steroids, it is important to keep all appointments with your
doctor and the laboratory and have your blood pressure checked regularly.
Because steroids increase your chance for developing an infection, report
symptoms such as a cough, fever or shortness of breath to your doctor.
Long-term steroid treatment (for a few months to several years) requires
additional testing and monitoring. The potential side effects caused by
long-term steroid therapy should be discussed with your doctor.
What is the long-term outlook?
With careful monitoring and appropriate treatment, most people with PMR or GCA
have a normal life span and lifestyle. The success of therapy is related to
prompt diagnosis, aggressive treatment and careful follow-up to prevent or
minimize side effects from the medications.
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