Polymyositis is a systemic connective tissue disease
characterized by inflammation and degeneration of the muscles
Information about Polymyositis
The cause of this disorder is unknown. It is thought that an
autoimmune reaction or a viral infection of the skeletal muscle may cause the disease. It
can affect people at any age, but most commonly occurs in those between 50 and 70 years
old, or in children between 5 and 15 years old. It affects women twice as often as men.
Muscle weakness may appear suddenly or occur slowly over weeks or months. There may be
difficulty raising the arms over the head, rising from a sitting position, or climbing
stairs. The voice may be affected through weakness of the throat muscles. Joint pain,
inflammation of the heart, and lung disease may occur.
A similar condition, called dermatomyositis, is evident when a dusky, red rash appears
over the face, neck, shoulders, upper chest, and back. A malignancy may be associated with
this disorder. Each year, between 2 and 10 people per million develop the disease./p>
Causes of Polymyositis
The cause of PM and DM is not known, but it is suspected that a variety of factors may
play a role in the development of these diseases. PM and DM may be autoimmune diseases,
caused by the immune system's attack on the body's own tissue. The reason for this attack
is unknown, although some researchers believe that a combination of immune system
susceptibility and an environmental trigger may explain at least some cases. Known
environmental agents associated with PM and DM include infectious agents such as Toxoplasma,
Borrella (Lyme disease bacterium), and coxsackievirus. Most cases, however, have no
obvious triggers (direct causative agents). There may also be a genetic component in the
development of PM and DM.
Symptoms of Polymyositis
- muscle weakness, proximal muscles (shoulders, hips, etc.)
- muscle pain
- difficulty swallowing
- shortness of breath
- hand tremor
The early symptoms of PM and DM are slowly progressing muscle weakness, usually
symmetrical between the two sides of the body. PM and DM affect primarily the muscles of
the trunk and those closest to the trunk, while the hands, feet, and face usually are not
involved. Weakness may cause difficulty walking, standing, and lifting objects. Rarely,
the muscles of breathing may be affected. Weakness of the swallowing muscles can cause
difficulty swallowing (dysphagia). Joint pain and/or swelling also may be present. Later
in the course of these diseases, muscle wasting or shortening (contracture) may develop in
the arms or legs. Heart abnormalities, including electrocardiogram (ECG) changes and
arrhythmias, develop at some time during the coursed of these diseases in about 30% of
Dermatomyositis is marked by a skin rash. The rash is dusky, reddish, or lilac in
color, and is most often seen on the eyelids, cheeks, bridge of the nose, and knuckles, as
well as on the back, upper chest, knees, and elbows. The rash often appears before the
Diagnosis of Polymyositis
PM and DM are often difficult diseases to diagnose, because they are rare, because
symptoms come on slowly, and because they can be mistaken for other diseases causing
muscle weakness, especially limb girdle muscular dystrophy.
Accurate diagnosis involves:
- A neurological exam.
- Blood tests to determine the level of the muscle enzyme creatine kinase, whose presence
in the circulation indicates muscle damage.
- Electromyography, an electrical
test of muscle function.
- Muscle biopsy, in which a small sample of affected muscle is surgically removed for
microscopic analysis. A biopsy revealing muscle cells surrounded by immune system cells is
a strong indicator of myositis.
Treatment of Polymyositis
The disease is treated with corticosteroid medications. When an
improvement in muscle strength is achieved, usually in 4 to 6 weeks, the medication is
slowly tapered off. Maintenance therapy with prednisone may be continued indefinitely. In
people who fail to respond to corticosteroids, medications to suppress the immune system
may be used.
If the condition is associated with a tumor, the condition
may improve if the tumor is removed.
Alternative treatment of Polymyositis
As with all autoimmune conditions, food allergies/intolerances and environemental
triggers may be contributing factors. For the food allergies and intolerances, an
elimination/challenge diet can be used under the supervision of a trained practitioner,
naturopath, or nutritionist, to identify trigger foods. These foods can then be eliminated
from the person's diet. For environmental triggers, it is helpful to identify the source
so that it can be avoided or eliminated. A thorough detoxification program can help
alleviate symptoms and change the course of the disease. Dietary changes from processed
foods to whole foods that do not include allergen trigger foods can have significant
results. Nutrient supplements, especially the antioxidants zinc, selenium, and vitamins A,
C, and E, can be beneficial. Constitutional homeopathic treatment can work at a deep level
to rebalance the whole person. Acupuncture and Chinese herbs can be effective in symptom
alleviation and deep healing. Visualization, guided imagery, and hypnosis for pain
management are also useful.
Prognosis of Polymyositis
Remission (a period when no symptoms are present) and recovery
occur in many patients, especially children. For most others, immunosuppressant drugs can
control the disease. In adults, death may result from severe and prolonged muscle
weakness, malnutrition, pneumonia, or respiratory failure.
The probable outcome is usually worse if there is chest involvement.
Complications of Polymyositis
- associated malignancy
- heart disease, lung disease, or abdominal complications
- calcium deposits in the affected muscles, especially in children with the disease