Juvenile dermatomyositis (JDM) is a rare disease of the skin, muscles, and blood vessels.
The exact cause of JDM is not known. It is thought to be a problem with the immune system. These problems may cause swelling of muscle cells and blood vessels that can lead to harm.
JDM is more common in girls, children living in North America, and children who are black. Children with a family history of type 1 diabetes and lupus are also at a higher risk.
The first JDM symptoms are:
- Lack of hunger
- Weight loss
As JDM gets worse, symptoms may be:
- Skin changes, such as:
- Purple, bumpy, or scaly skin rash on the face, eyelids, knuckles, elbows, knees, chest, and back
- Skin sores
- Muscle problems, such as:
- Weakness, especially in the muscles closest to the trunk
- Problems swallowing and speaking
- Problems moving from sitting or standing
- Sore throat
- Belly pain
- Shortness of breath
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You will be asked about your child's symptoms and health history. A physical exam will be done. It will focus on your child's skin and muscles.
Your child’s blood and urine will be tested. This will look for changes in some enzymes.
Your child's muscles may be tested using:
Electromyography is an electrical test that can find nerve or muscle damage.
There is no cure for JDM. Some children may have times when symptoms lessen or go away. Treatment will focus on managing symptoms. Talk with the doctor about the best plan for your child. Choices are:
Medicine will be given to help ease symptoms. These may be:
- Corticosteroids, methotrexate, or cyclosporine to ease inflammation and suppress the immune system
- Mycophenolate mofetil to suppress the immune system in people with severe symptoms
- Hydroxychloroquine to ease a rash
IV immunoglobin (IVIG) may be given to slow down the inflammatory process.
Exercise can help when the inflammation is under control. It can:
- Maintain and improve strength and flexibility
- Prevent muscle wasting and stiffness
Speech therapy can help teach children how to cope with problems swallowing. A dietitian can also help with meal planning.
Skin protection is needed to control the rash and skin sores:
- Time in the sun will need to be limited. Peak hours will need to be avoided.
- Long-sleeved shirts and long pants, a wide-brim hat, and sunglasses should be worn in the sun.
- Sunscreen should have a sun protection factor (SPF) of at least 30.
There is no way to prevent JDM. The cause is not known.
American College of Rheumatology
Healthy Children—American Academy of Pediatrics
Canadian Rheumatology Association
Dermatomyositis. EBSCO DynaMed website. Available at:https://www.dynamed.com/condition/dermatomyositis. Updated June 4, 2018. Accessed July 18, 2019.
Dermatomyositis (juvenile). American College of Rheumatology website. Available at: http://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Dermatomyositis-Juvenile. Updated March 2019. Accessed July 18, 2019.
Enders FB, Bader-Meunier B, et al. Consensus-based recommendations for the management of juvenile dermatomyositis. Ann Rheum Dis. 2017 Feb;76(2):329-340.
Juvenile dermatomyositis. Arthritis Foundation website. Available at: http://www.arthritis.org/about-arthritis/types/juvenile-dermatomyositis-jd/. Accessed July 18, 2019.
Juvenile dermatomyositis. Stanford Children’s Health website. Available at: http://www.stanfordchildrens.org/en/topic/default?id=juvenile-dermatomyositis-90-P01714. Accessed July 18, 2019.
Last reviewed June 2019 by EBSCO Medical Review BoardKari Kassir, MD Last Updated: 4/22/2022