Dermatomyositis

Dermatomyositis (pronounced dur-muh-toe-my-uh-SY-tis) is a disease that affects the skin and muscles. It is one of three inflammatory myopathies. A myopathy is a disease of the muscles. Dermatomyositis is very rare and causes inflammation of the muscles and tissues, a distinct skin rash, and muscle weakness and tightness. The cause of dermatomyositis is unknown, and no cure exists. While some ailments caused by the disease can be severe, the disease itself is not life threatening. Many people with it experience periods of remission (periods of improvement) and learn how to manage the disease and issues it causes. Dermatomyositis affects both children and adults but is more likely to affect women than men.

Background

Dermatomyositis occurs in adults usually around the late forties to early sixties; in children, it can appear between ages five and fifteen years. The disease affects more women than men, but it is not known why.

No exact cause has been found for dermatomyositis. It has been linked to an autoimmune disorder in which the disease causes healthy cells in the body to attack the body's antibodies, or disease-fighting cells. In dermatomyositis, the cells attack the blood vessels in the muscles and the skin, causing inflammation and damage.

While dermatomyositis is not a hereditary disease, people who develop it could share several genetic factors. People with compromised immune systems such as those who have cancer, viral infections, or HIV/AIDS are more susceptible to contracting dermatomyositis. Another link is exposure to certain drugs, including the anesthetic carticaine, penicillamine (lowers copper levels in the body), interferon alpha (for cancer and hepatitis), cimetidine (treats ulcers), carbimazole (for thyroid disease), phenytoin (controls seizures), and certain growth hormones. Those who have gotten the hepatitis B vaccine also have reported cases of dermatomyositis.

The progression of dermatomyositis is gradual. All inflammatory myopathies cause discomfort, but they usually do not lead to severe conditions. No cure exists for dermatomyositis, but with the correct treatment, people can manage their symptoms and live normal lives. They can clear skin rashes and regain muscle strength. In addition, most people usually partially or completely recover from dermatomyositis or go through stretches of time in which the disease is inactive.

Overview

A change in the skin is the most obvious sign of dermatomyositis. Those with the disease usually develop a bluish-purplish-reddish and spotty rash. This can occur on a wide variety of places on the body such as the back, chest, elbows, eyelids, face, knees, knuckles, and nails.

Next, patients typically feel muscle fatigue, tightness, and pain in areas such as the arms, hips, neck, shoulders, or thighs. The condition can affect muscles on both sides of the body, and pain and inflammation can gradually worsen over time. Muscle soreness and inflammation can cause a host of other problems—some severe ones. Tight chest muscles may affect a person's breathing. Muscles in the esophagus that constrict could cause dysphagia (difficulty swallowing), which can lead to weight loss, malnutrition, and a condition known as aspiration pneumonia, or the breathing in of foods and liquids into the lungs.

Inside the body, the blood vessels in muscle tissues are the most affected by dermatomyositis. The inflammation caused by the condition can lead to the degeneration of muscle tissues. Dermatomyositis also can cause calcinosis, the deposit of calcium on the muscles, skin, and connective tissues. This is more common in children than in adults.

Other serious complications are associated with dermatomyositis. It can lead to a condition known as Raynaud's phenomenon (also called Raynaud's syndrome), in which some parts of the body (cheeks, ears, fingers, nose, and toes) feel numb or cold because of low temperatures or stress. This can affect blood circulation to these parts of the body. Dermatomyositis also can lead to other skin and connective tissue disorders such as scleroderma, the immune system disorder Sjogren's syndrome, and other inflammatory conditions such as lupus or rheumatoid arthritis.

Cardiovascular disease is a concern for those with dermatomyositis because the muscles around the heart could become inflamed, also known as myocarditis. This can lead to congestive heart failure or arrhythmia, which is an irregular heartbeat. The condition can cause fibrosis (scarring) of lung tissue that can make the lungs stiff and lose elasticity, leading to lung disease. Those with dermatomyositis who develop a dry cough and shortness of breath should be evaluated for possible lung problems.

Adults with dermatomyositis are at an increased risk of developing cancer of the breasts, cervix, gastrointestinal tract, lungs, ovaries, and pancreas. The risk is the highest during the first three years after the onset of symptoms of dermatomyositis. After this time, the likelihood of developing cancer in tandem with dermatomyositis decreases. Age is also a factor as older individuals with dermatomyositis are at a higher cancer risk.

Several tests can be performed to determine the presence of dermatomyositis. These include blood analysis to check for antibodies, chest x-ray to assess lung damage associated with the disease, electromyography to test the muscles, magnetic resonance imaging (MRI) of the muscles, and biopsy of the skin or muscles.

Several treatments exist to ease the symptoms of the condition. Pain medication can help people manage muscular pain. The most common medication used is a corticosteroid, which reduces inflammation-causing antibodies. However, corticosteroids have serious side effects when taken for a long period; therefore, they are usually prescribed with corticosteroid-sparing medications to reduce the side effects. Intravenous immunoglobulin (IVIg), which is a transfusion of blood containing healthy antibodies, may help to block the antibodies attacking the healthy cells in the body.

Physical therapy can help patients regain use and control of muscles as well as improve strength and flexibility. Patients with dysphagia related to dermatomyositis may need speech therapy and help from a dietician to learn how to prepare meals that are easy to chew and swallow. Surgery is sometimes used to remove calcium deposits.

Bibliography

"Dermatomyositis." Mayo Clinic, 17 June 2014, www.mayoclinic.org/diseases-conditions/dermatomyositis/basics/definition/con-20020727. Accessed 28 Oct. 2016.

"Dermatomyositis." MedlinePlus, 20 Jan. 2015, medlineplus.gov/ency/article/000839.htm. Accessed 28 Oct. 2016.

"Dermatomyositis (DM)." Muscular Dystrophy Association, www.mda.org/disease/dermatomyositis. Accessed 28 Oct. 2016.

"Dermatomyositis." National Organization for Rare Disorders, rarediseases.org/rare-diseases/dermatomyositis. Accessed 28 Oct. 2016.

Femia, Alisa N. "Dermatomyositis." Medscape, 20 Jan. 2016, emedicine.medscape.com/article/332783-overview. Accessed 28 Oct. 2016.

Hajj-ali, Rula A. "Polymyositis and Dermatomyositis." Merck Manual Professional Version, June 2013, www.merckmanuals.com/professional/musculoskeletal-and-connective-tissue-disorders/autoimmune-rheumatic-disorders/polymyositis-and-dermatomyositis. Accessed 28 Oct. 2016.

"NINDS Dermatomyositis Information Page." National Institute of Neurological Disorders and Stroke, 27 July 2015, www.ninds.nih.gov/disorders/dermatomyositis/dermatomyositis.htm. Accessed 28 Oct. 2016.

Wint, Carmella, and Marijane Leonard. "Dermatomyositis." Healthline, 18 Nov. 2015, www.healthline.com/health/dermatomyositis#Overview. Accessed 28 Oct. 2016.