Dermatomyositis (DM), a form of myositis, is a chronic, rare systemic autoimmune disease affecting approximately 80,000 people in the U.S., EU and Japan.1 The disease is typically diagnosed when a person is between 50 and 60 years old, and women are more commonly affected than men.2,3 DM is characterized by skin rash and muscle weakness, alone or together. DM is caused by chronic activation of the immune system, which causes inflammation in the skin, the muscles and other organs, damaging these body parts.
The symptoms of DM vary depending on the severity of the disease. Typically, a skin rash appears and precedes, accompanies, or follows progressive muscle weakness. DM rash, which can be painful and intensely itchy, looks patchy and reddish or purple. Some people also have deposits of calcium in the skin and in the muscles called calcinosis. People affected by DM may experience weight loss, trouble swallowing, muscle pain, fatigue, inflamed lungs, and be sensitive to light.4 Long-standing muscle atrophy and weakness are also common and may require the use of mobility aids. Additionally, other organs, including the lungs and the heart, can also be affected. Mortality in people with DM is high and estimated to be 30% at 5 years.5
There is no cure for DM, a disease that continues to progressively worsen over time.6,7 Typically, people with DM are prescribed drugs that suppress the immune system. These treatments may be associated with significant side effects, such as serious infections.8 FDA-approved treatments for DM include systemic corticosteroids and adrenocorticotropic hormone analogue.9,10
What Is it Like to Live with Dermatomyositis?
Emily, living with dermatomyositis, discusses her symptoms and her long roads to diagnosis. Jerry speaks about being diagnosed with myositis and how the disorder has affected his life.
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2. Tansley, Sarah L, et al. “Adult and Juvenile Dermatomyositis: Are the Distinct Clinical Features Explained by Our Current Understanding of Serological Subgroups and Pathogenic Mechanisms?” Arthritis Research & Therapy, vol. 15, no. 2, 8 Apr. 2013, p. 211., doi:10.1186/ar4198
3. Bernatsky, S, et al. “Estimating the Prevalence of Polymyositis and Dermatomyositis from Administrative Data: Age, Sex and Regional Differences.” Annals of the Rheumatic Diseases, vol. 68, no. 7, July 2009, pp. 1192–1196., doi:10.1136/ard.2008.093161
4. “Dermatomyositis Information Page.” National Institute of Neurological Disorders and Stroke, U.S. Department of Health and Human Services, 12 June 2018, www.ninds.nih.gov/Disorders/All-Disorders/Dermatomyositis-Information-Page
5. Schiopu, Elena, et al. “Predictors of Survival in a Cohort of Patients with Polymyositis and Dermatomyositis: Effect of Corticosteroids, Methotrexate and Azathioprine.” Arthritis Research & Therapy, vol. 14, no. 1, 2012, doi:10.1186/ar3704
6. “Dermatomyositis Information Page.” National Institute of Neurological Disorders and Stroke, U.S. Department of Health and Human Services, 12 June 2018, www.ninds.nih.gov/Disorders/All-Disorders/Dermatomyositis-Information-Page
7. Marie, Isabelle. “Morbidity and Mortality in Adult Polymyositis and Dermatomyositis.” Current Rheumatology Reports, vol. 14, no. 3, 2012, pp. 275–285., doi:10.1007/s11926-012-0249-3
8. Dalakas, Marinos C. “Immunotherapy of Myositis: Issues, Concerns and Future Prospects.” Nature Reviews Rheumatology, vol. 6, no. 3, Mar. 2010, pp. 129–137., doi:10.1038/nrrheum.2010.2
9. FDA label Orapred ODT, available at https://www.accessdata.fda.gov/drugsatfda_docs/label/2010/021959s004lbl.pdf; accessed 04 Sept 2018
10. FDA label H.P. Acthar gel, available at https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/008372s057lbl.pdf; accessed 04 Sept 2018