How to Identify Myositis

Myositis is the inflammation of the muscles within the body. Inflammation of the skeletal muscles occurs because of an infection, injury or autoimmune disease. According to the Johns Hopkins Myositis Center, diagnosing the condition requires multiple medical tests and a thorough physical examination. Myositis can be temporary because of injury or it can be chronic due to an autoimmune disorder. The chronic form has periods of activity followed by times of remission. Even after treatment begins, the active phase of the condition may last for two to three years.

Instructions

• 1

  Assess muscle weakness in the body. According to Johns Hopkins Myositis Center, the most frequently affected muscles are closest to the trunk of the body. Weakness while climbing stairs and raising hands over the head provide valuable clues in assessing muscle strength in the hips and shoulders.

• 2

  Evaluate for pain in the skeletal muscles during movement and for fatigue. According to the Arthritis Foundation, myositis may also cause the muscles to be painful when touched. Fatigue of specific affected muscles as well as overall body fatigue may occur.

• 3

  Assess skin for a rash. A rash, primarily on the eyelids, face, knuckles, knees, elbows, upper chest and back, characterizes dermatomyositis (DM), one type of myositis. According to the Myositis Association, the appearance of the rash is dry, scaly and reddish-purple in color.

• 4

  Obtain a blood sample to evaluate for elevated muscle enzymes and myositis antibodies. An increase in autoimmune antibodies indicates the condition is an autoimmune form, and not from medications or a virus.

• 5

  Perform a biopsy of skin and muscle tissue samples. Look for inflammation and damage in the muscles under the microscope, according to the Arthritis Foundation. White blood cells in the muscle indicate an autoimmune response.

• 6

  Scan muscles with a magnetic resonance imaging (MRI) scanner to visualize inflammation, the Myositis Association says. An MRI is a valuable tool in evaluating the muscle because of the ability to view a large area at one time, and the test is noninvasive.

• 7

  Use an electromyogram (EMG) to detect electrical changes within the muscles. An EMG stimulates muscles and measures the electricity in the muscle while moving and at rest. A muscle affected by myositis has a different electrical pattern than normal muscles or ones affected by a separate muscular disorder.