Dermatomyositis, an inflammatory disease marked by muscle weakness and skin rash, was first described in 1975. It is characterized by progressive proximal symmetrical weakness (progressive weakening of muscles on both sides of the body), above-normal muscle enzyme levels, an abnormal electromyography reading (a measure of nerve impulses in the muscles), an abnormal muscle biopsy (a test in which muscle tissue is examined), and skin disease.
There are three different subcategories of this disease: childhood dermatomyositis, adult dermatomyositis, and dermatomyositis sine myositis (in which a person experiences skin symptoms but not the muscle symptoms).
The causes of dermatomyositis are unknown, but it may result from a problem with the immune system or from a viral infection. There have been case reports linking the disease to drugs such as statins, penicillamine, quinidine, and phenylbutazone.
It is estimated that there are 9.63 cases of dermatomyositis per million people. The disease may present at any age, but onset peaks in childhood and in late adulthood. Dermatomyositis is half as common in men as women. It may cause severe disability or death due to muscle weakness or involvement of vital organs such as the heart.
The National Institute of Neurological Disorders and Stroke (NINDS), along with the National Institute of Health (NIH), is funding research into gene expression patterns in the disease, the role of viral infection, and the safety of various treatments, including those currently in practice.

Related Terms

Adult dermatomyositis, amyopathic dermatomyositis (ADM), childhood dermatomyositis, dermatomyositis sine myositis, idiopathic inflammatory myopathy (IIM), juvenile dermatomyositis, polymyositis.

types of the disease

There are three forms of the disease, which vary in terms of the symptoms they commonly cause.
Childhood dermatomyositis: Childhood dermatomyositis most commonly occurs in children aged 5-15, and abnormal calcium deposits (also known as calcifications) in the muscles, skin, and digestive tissues are common.
Adult dermatomyositis: Adult dermatomyositis generally occurs in a person's late 40s to early 60s, and generally has a more gradual onset than the childhood version of the disease. Calcifications are less common in the adult onset form of the disease.
Dermatomyositis sine myositis: Dermatomyositis sine myositis results in skin symptoms, but none of the myopathic (muscular) symptoms.