Definition

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

Causes

The exact cause 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.

Risk Factors

This problem is more common in girls. Other things that may raise the risk are:

• Having certain gene mutations
• Connective tissue disorders
• Infections, such as coxsackie B virus
• Certain drugs and procedures

Symptoms

The first JDM symptoms are:

• Fever
• Tiredness
• Lack of hunger
• Weight loss

As JDM gets worse, symptoms may be:

• Skin changes, such as:
  • A 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
  • Pain
  • Problems swallowing and speaking
  • Problems moving from sitting or standing
  • Falls
• Sore throat
• Belly pain
• Shortness of breath

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Diagnosis

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 high levels of muscle enzymes.

Images may be taken. This can be done with an MRI scan.

Your child's muscles may be tested. This can be done with:

• A muscle biopsy
• Electromyography—an electrical test to look for nerve or muscle damage

Treatment

There is no cure. Some children may have times when symptoms lessen or go away. Symptoms will need to be managed. Choices are:

Prevention

There are no known methods to prevent this health problem.