What is juvenile dermatomyositis?
Dermatomyositis is a rare disease that causes muscle inflammation and skin rash. It’s one of a group of muscle diseases that cause muscle inflammation and swelling. It's different from other muscle diseases because it also causes skin problems. Dermatomyositis is the term used to describe both muscle and skin symptoms. Juvenile dermatomyositis is the condition most often seen in children.
What causes juvenile dermatomyositis?
The exact cause is not yet known. But it may be linked to problems with the immune system that result in infections.
What are the symptoms of juvenile dermatomyositis?
The symptoms often appear slowly over time. In some cases, they may happen more quickly or severely. Symptoms can occur a bit differently in each child. They can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis. The most common symptoms of juvenile dermatomyositis include:
- Rash around the eyelids, knuckles, or finger joints
- Rash on the elbows, knees, and ankles
- Muscle weakness
- Ill feeling (malaise)
- Muscle pain and tenderness
- Irritable mood
- Trouble swallowing
- Weight loss, due to trouble swallowing
- Joint pain and inflammation
- Calcium deposits under the skin (calcinosis)
- Mouth ulcers
The course of the illness is often divided into 4 phases:
- Prodromal period. This phase can last for weeks or months. The symptoms seen during this period are general symptoms that are like many health conditions, such as fever and fatigue.
- Increasing muscle weakness and rash. In this phase, muscle weakness increases for days and weeks and then becomes stable. Once the muscle weakness is stable, it may last from one to two years before recovery.
- Continuing muscle weakness, muscle inflammation, and rash. During this phase, symptoms include continuing muscle weakness, active inflammation of the muscles, and rash lasting up to two years.
- Recovery. Recovery may occur without any aftereffects. Or it may occur after 2 or more years with some symptoms. These may include continuing muscle weakness and muscle atrophy (wasting). Some muscles may have or contractures. This is a condition in which some muscles in may become paralyzed in a contracted position.
How is juvenile dermatomyositis diagnosed?
The process starts with your child's medical history and a physical exam. Your child may also have tests, such as:
- Blood tests. These tests are used to assess the presence of antibodies, muscle enzymes, and signs of inflammation.
- Electromyelogram (EMG). This is an electrical test that may be done to find nerve or muscle damage.
- MRI. This test uses large magnets and a computer to look for inflammation in the body.
- Muscle biopsy. Tiny pieces of tissue are taken to be checked with a microscope.
- X-rays. A small amount of radiation is used to create pictures of internal tissues, bones, and organs.
How is juvenile dermatomyositis treated?
Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is. There's no cure for the condition, but the symptoms can be managed. And the disease may go into remission. Treatments may include:
- Medicines. Glucocorticosteroids and methotrexate may be used to treat inflammation. Hydroxychloroquine may be used to help treat the skin symptoms.
- Physical and occupational therapy. This can help to improve muscle function and strength.
- Use of sunscreen. Sunscreen helps to prevent more irritation or damage to the skin.
- Nutritional support. A healthy diet will help support the body during the disease.
Talk with the healthcare providers about the risks, benefits, and possible side effects of all medicines.
What are the complications of juvenile dermatomyositis?
Many children will recover without any lasting problems. Some children may have mobility issues due to contractures of the joints. Other children may have chronic symptoms. These may include pain, muscle weakness, and delayed growth. There may be damage to bones, joints, lungs, and other internal organs.
Helping your child live with juvenile dermatomyositis
Juvenile dermatomyositis can make it hard for a child to take part in school and other activities. Work with your child’s school to help teachers and caregivers understand your child’s limits. A healthy lifestyle can help improve your child’s quality of life. This includes a good diet, exercise, and rest. A support group may help your child feel less alone or different.
When should I call my child’s healthcare provider?
If your child's symptoms get worse or he or she has new symptoms, let the healthcare provider know.
Key points about juvenile dermatomyositis
- Juvenile dermatomyositis causes muscle damage due to inflammation.
- Symptoms include fever, rash, muscle weakness and pain, and calcium deposits under the skin.
- The condition also causes a rash around the eyelids, knuckles, or finger joints. A rash may also occur on the elbows, knees, and ankles.
- The types of treatment include medications, physical therapy, and a healthy lifestyle.
- A child may have a complete remission of the disease. Others may have chronic symptoms that continue.
Tips to help you get the most from a visit to your child’s healthcare provider:
- Before your visit, write down questions you want answered.
- At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you for your child.
- If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.