Muscle Diseases - Dermatomyositis Is One Of A Group Of Inflammatory Muscle Diseases

Dermatomyositis is one of a group of three related diseases which is known as inflammatory myopathies. The exact cause of dermatomyositis is still unknown. In a healthy body, cells of the immune system attack only the foreign or defective cells in the body in order to protect it from disease. In an autoimmune disease, the immune system attacks most of the normal body cells. In the case of DM, immune system cells attack the healthy cells of the small blood vessels in the muscle as well as the skin. Over time, this causes the muscle fiber to shrink and sometimes cuts off the main blood supply to the muscle.

As yet, there is no clear explanation of what actually causes an individual to develop DM. It is thought that the disease could be triggered by a virus or an exposure to certain drugs or even vaccines. According to the Muscular Dystrophy Association, recent research suggests developing DM may be linked to the mixing of blood cells that sometimes occurs between the mother and the fetus during pregnancy. The disease may not be directly inherited but there may be some sort of genetic sensitivity toward whatever triggers it.

Generally the first sign of DM is the development or visibility of a patchy, scaly, and violet to dark red skin rash on the face, neck, shoulders, upper chest, knees, or back. Mostly the rash appears before any signs of illness or even muscle weakness. Approximately 40% of children and teens develop hard, painful bumps under the skin that are deposits of calcium, a mineral used in bone formation. This condition known as calcinosis and is much less common in adults.

Muscle weakness, especially in the upper arms, hips, thighs, and neck, becomes quite apparent in activities such as during climbing stairs or even reaching up over the head. This kind of weakness develops after the rash appears. Some people have difficulty in swallowing and chewing when the muscles of the face and esophagus are badly affected. Individuals can also feel tried, weak; have a low-grade fever, weight loss, and even joint stiffness.

Some individuals have the rash for years before they even progress to these symptoms, while in others the onset of symptoms is quite fast. In children the development of symptoms is mostly gradual, making diagnosis especially difficult. DM can be difficult to diagnose sometimes, and often the first doctor an individual sees is a dermatologist for such a treatment of the rash and then is referred to a rheumatologist who is a specialist in internal medicine or neurologist when DM is suspected.

Many tests may be done to rule out the other diseases before a firm diagnosis or decision is made. A blood test is normally done to measure the level of creatine kinase. Creatine kinase is an enzyme mostly found in muscle tissue. When the muscle is damaged then this enzyme leaks out into the blood. Another blood test could be done to test for specific immune system antibodies. Antibodies are a protein made in response to the material that the body thinks is foreign.

• Felicia Byrnes
• 17/06/2009, 6:59 AM
• 0 Comments