Degenerative changes of the muscles and skin, caused by an inappropriate autoimmune reaction that leads to obstructive inflammatory changes of blood vessels within muscle, connective tissues of the skin, and other tissues.

There are three types of DM:

Adult dermatomyositis
Sine myositis
Juvenile dermatomyositis (JDMS)

Common Symptoms

Muscle weakness, stiffness and soreness, difficulties in swallowing (dysphagia) and articulating speech (dysphonia), reddish-purple rash (heliotrope) present in eyelids, on forehead, cheeks, and bridge of the nose, scaly regions of skin, a “dusky” rash which is itchy, fatigue, and weight loss.
Symptoms specific to each of the three types of the DM: 

  • adult dermatomyositis: low-grade fever, lung inflammation, and sensitivity to light
  • sine myositis: skin abnormalities may occur without associated muscle abnormalities 
  • juvenile dermatomyositis (JDMS): Similar symptoms to the adult form but with a more sudden onset. Abnormal accumulations of calcium deposits in muscle and skin tissues and GI tract involvement are more common here.

Coexisting Diseases and Conditions

Malignancies (in adult form), SLE, rheumatoid arthritis, Sjorgren’s syndrome, cardiovascular disease, scleroderma, and interstitial lung disease.

Risk Factors and Prevalence

Like many other autoimmune conditions, DM affects more females, with a 2:1 ratio of females to males affected. Viral infections such as Epstein-Barr and coxsackievirus may also cause the condition. Environmental factors such as exposure to smoking, UV radiation, and air pollution have also been associated with DM, and maternal exposure to these factors increases the risk for juvenile dermatomyositis. Lastly, studies have pointed to collagen dermal implants resulting in cases of DM.


  1. Article Sources
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    5. Jakubaszek, M., Kwiatkowska, B., & Maślińska, M. (2015). Polymyositis and dermatomyositis as a risk of developing cancer. Reumatologia, 53(2), 101–105.

    6. Miller, F. W., Lamb, J. A., Schmidt, J., & Nagaraju, K. (2018). Risk Factors and Disease Mechanisms in Myositis. Nature Reviews. Rheumatology, 14(5), 255–268.

    7. Orione, M. A. M., Silva, C. A., Sallum, A. M. E., Campos, L. M. A., Omori, C. H., Braga, A. L. F., & Farhat, S. C. L. (2014). Risk factors for juvenile dermatomyositis: Exposure to tobacco and air pollutants during pregnancy. Arthritis Care & Research, 66(10), 1571–1575.

    8. Peravali, R., Acharya, S., Raza, S. H., Pattanaik, D., & Randall, M. B. (2020). Dermatomyositis Developed After Exposure to Epstein-Barr Virus Infection and Antibiotics Use. The American Journal of the Medical Sciences, 360(4), 402–405.