Dermatomyositis is a group of muscle diseases known as inflammatory myopathies. This muscle disease is characterized by the presence of chronic muscle inflammation, muscle weakness and distinctive skin rash. The onset in adults is usually in the age group of 50 to 70 and appears to affect more women than men. Among the children, it affects the age group of 5 and 15 years. Although the affected individuals respond well to treatment, complications can develop in those with the severe form of this condition that involves the cardiac or the pulmonary system. In most cases, this is not a life-threatening condition and treatments can enable recovery possible.
Causes
The cause of this condition is not completely clear. It is believed to be an autoimmune condition when the body accidentally damages the muscle tissue. The small blood vessels are particularly affected that can result in the degeneration of the muscle. Although this is not a genetically inherited condition, genetic factors can predispose the individual to develop dermatomyositis. Some of the other contributing factors for developing this condition can include certain triggering infections, underlying cancer and exposure to toxic agents.
Symptoms
The initial sign of dermatomyositis is the itchy, burning rash. It can be reddish or purple patches that can occur in the areas of the eyelids, knuckles, cheeks, nose, shoulder, upper chest and the elbows. The prominent blood vessels are evident on the nail folds and hair thinning on the scalp may also occur. Additional symptoms include a condition known as calcinosis which is the hard lumps under the skin which can become infected. The muscle weakness occurs which usually affects the areas of the shoulders, neck, thigh, upper arms and the hips. Inflammation of the heart muscle tissue and the lungs can also develop.
Diagnosis
The diagnosis may be based on the evaluation of the individual’s medical history and with a physical examination. Other diagnostic tests can include blood analysis to determine the presence of certain muscle enzymes such as creatine kinase which is an indication of muscle damage and electromyography which measures the electrical activity of the muscle. Additional tests can include a chest x-ray to assess damage to the lungs and skin biopsy to determine the inflammation of the muscle or the presence of infection or damage.
Treatment
There is no cure for this disease but treatment can relieve the symptoms. Early treatment is necessary to prevent the complications. The treatment options include medications, heat therapy, exercise, physical therapy and assistive devices. Medications may be administered to suppress the immune system in some of the cases. Physical therapy can improve and strengthen the muscles. Surgical intervention may be necessary to remove the calcium deposits and to prevent skin infections.
References
http://www.mayoclinic.org/diseases-conditions/dermatomyositis/basics/treatment/con-20020727
http://www.dermnetnz.org/topics/dermatomyositis/
http://www.ninds.nih.gov/disorders/dermatomyositis/dermatomyositis.htm