What is Myositis ?

Dermatomyositis

Dermatomyositis is characterized by a rash that precedes or accompanies muscle weakness. The cause is unknown. The rash that accompanies the symptoms of muscle weakness looks like patchy, bluish-purple discolourations on the face, neck, shoulders, upper chest, elbows, knees, knuckles, or back. Some people may also develop calcium deposits, which appear as hard bumps under the skin.

The most common symptom of dermatomyositis is muscle weakness, usually affecting the muscles that are closest to the trunk of the body. Some patients also have lung involvement, which can cause difficulty breathing.

Risk Group

People all over the world can suffer from dermatomyositis. Women are at least two times more likely to suffer from dermatomyositis than men.

Symptoms

1. The gradual onset of weakness over weeks or months
2. Difficulty rising from a low-seated chair or combing one’s hair.
3. Torso or “core” weakness
4. Difficulty swallowing (dysphagia)
5. Pain or weakness in the joints
6. Generalized fatigue
7. Patchy, reddish rash on the eyelids, cheeks, bridge of the nose, back or upper chest, and joints. In some cases, the development of hardened bumps under the skin.
8. Diagnostic Tests
9. Your doctor will ask for a complete medical history and will perform a thorough physical examination.
10. Blood work will be obtained.
11. Electromyography (EMG) and nerve conduction tests may be performed.
12. Magnetic resonance imaging (MRI) of affected muscle may be requested.
13. After the doctor sees you and reviews the results of your testing, a muscle biopsy may be required to confirm the diagnosis of dermatomyositis. This is a minor procedure that can be performed by a doctor at the Johns Hopkins Myositis Center.

Treatment

If you have dermatomyositis, your doctor will most likely prescribe medications that suppress the immune system, such as corticosteroids and immunomodulators LIKE METHOTREXATE, AZORAN, mYCOPHENOLATE MOFETIL OR CYCLOPHOSPHAMIDE.

Inclusion body myositis (IBM) is an inflammatory muscle disease characterized by progressive muscle weakness and wasting. Patients suffering from IBM usually develop symptoms of IBM after age 50; however, some patients may present with symptoms as early as their 30’s. Patients typically develop difficulty in swallowing (dysphagia), weak wrists or fingers and atrophy of the forearms and/or thigh muscles.

Unlike other forms of myositis, IBM is approximately two times more common in men than in women.

Symptoms

muscle weakness often progresses slowly over months or years weakness in the thighs, wrists and fingers

the difficulty in swallowing (dysphagia)

patients may have a history of frequent falls

Diagnostic Tests

Your doctor will ask for a complete medical history and will perform a thorough physical examination. Certain blood tests will be ordered, and a muscle biopsy may be performed. The muscle biopsy is a minor procedure. A local anaesthetic is applied, and a small piece of muscle is removed – usually from a thigh muscle or shoulder muscle. The biopsy is one of the critical diagnostic tests to determine whether you suffer from inclusion body myositis.

treatments

If you have inclusion body myositis, your doctor may prescribe medications that suppress the immune system, such as corticosteroids. Unfortunately, however, many patients with inclusion body myositis do not respond as well to these medications as do patients with polymyositis or dermatomyositis.

Polymyositis

Polymyositis is a disease caused by inflammation of the muscles. This occurs when white blood cells, the immune cells of inflammation, begin to invade the muscle tissue. The muscles most severely affected are typically those closest to the trunk or torso. This results in weakness that can be severe.

Some patients with polymyositis also have lung involvement, which can cause difficulty breathing.

Risk Group

The incidence of polymyositis increases with age, with the highest rates being seen in the 35-44 and 55-64-year-old age groups. Women are two times more likely to suffer from polymyositis than men.

Symtoms

The gradual onset of weakness over weeks or months

Difficulty rising from a low-seated chair or combing one’s hair

Torso or “core” weakness

Difficulty swallowing (dysphagia)

Pain or weakness in the joints

Generalized fatigue

Diagnostic Tests

Your doctor will ask for a complete medical history and will perform a thorough physical examination.

Blood work will be obtained.

Electromyography (EMG) and nerve conduction tests may be performed.

Magnetic resonance imaging (MRI) of affected muscle may be requested.

After the doctor sees you and reviews the results of your testing, a muscle biopsy may be required to confirm the diagnosis of polymyositis.

Treatments

If you have polymyositis, your doctor will most likely prescribe medications that suppress the immune system, such as corticosteroids and immunomodulators.