Definition

Juvenile dermatomyositis (JDM) is a rare disease of the skin, muscles, and blood vessels.

Causes

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 damage.

Risk Factors

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.

Symptoms

The first JDM symptoms are:

• Fever
• Fatigue
• Lack of hunger
• Weight loss

As JDM gets worse, symptoms may be:

• Skin changes, such as:
  • Violet-colored, 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
  • Pain
  • Problems swallowing and speaking
  • Problems moving from a seated to a standing position
  • Falling often
• Sore throat
• Belly pain
• Shortness of breath

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Diagnosis

You will be asked about your symptoms and health history. A physical exam will be done. It will focus on your skin and muscles. The appearance of a rash may help with diagnosis.

Your child’s blood and urine will be tested. This will look for changes in some enzymes and signs of swelling.

Your muscles may be tested using:

• MRI
• Biopsy of your child’s muscle

Electromyography is an electrical test that can find nerve or muscle damage.

Treatment

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:

Prevention

There is no way to prevent JDM. The cause is not known.