Juvenile dermatomyositis (JDM) can seriously impact your child’s daily life, and can also tax the emotional health of your family. Since it’s so rare, juvenile dermatomyositis (JDM) can seem scary to family and child—and often it’s puzzling to pediatricians, who may not be familiar with the condition. But within the Rheumatology Programat Children’s Hospital Boston, JDM is actually the most common condition we see after arthritis. And the good news is that with proper treatment, it can be well managed.
The information on the following pages is a good starting point to help you learn more about JAD and to give you and your family a general idea of what to expect in the weeks and months ahead.
What is juvenile dermatomyositis?
Juvenile dermatomyositis is a rare autoimmune disorder in which the immune system attacks blood vessels throughout the body (called vasculopathy), causing muscle inflammation (known as myositis). As a result, your child may be exhausted by simple, everyday activities, like walking up stairs or lifting a backpack, or he may have trouble keeping up with friends at recess or on the soccer field. Often it is not until the condition appears in the form of a rash around the eyelids or over the knuckles or finger joints, that parents seek medical attention.
How common is juvenile dermatomyositis?
Juvenile dermatomyositis is rare, affecting only 3,000 to 5,000 children in the United States under age 18.
Are there any significant side effects to juvenile dermatomyositis?
Juvenile dermatomyositis can result in calcinosis, which are calcium deposits under the skin, around the joints and in the intramuscular facial planes. Mild cases of calcinosis are usually cleared with treatment, but in some cases, calcinosis can cause chronic severe pain, joint contractures (a condition in which muscles in a particular location may become permanently paralyzed), fever and other complications.
Here at Children’s, we have conducted numerous studies of the formation and treatment of calcinosis—specifically early, aggressive treatment—with the goal of uncovering the most effective way to manage it.
What are the different phases of juvenile dermatomyositis?
The course of juvenile dermatomyositis has historically been divided into four phases:
Prodromal period: This phase can last for weeks or months. JDM is difficult to diagnose in this phase because the symptoms are so nonspecific.
Progressive muscle weakness and rash: In this phase, muscle weakness increases for days and weeks and then stabilizes. Once the stabilization occurs, it may last for several years before a child fully recovers.
Persistent muscle weakness, muscle inflammation and rash: During this phase, symptoms include persistent muscle weakness, active inflammation of the muscles and a rash lasting up to two years.
Recovery: Recovery may occur after two or more years with residual muscle weakness, atrophy (wasting of the muscles), or contractures—a condition in which muscles in a particular location may become permanently paralyzed. Other times, a child recovers without any apparent long-term effects.
What causes juvenile dermatomyositis?
Doctors don’t fully understand what causes juvenile dermatomyositis. However, we think that certain children have a genetic predisposition to it. Factors thought to be associated with the condition include problems with the immune system that are triggered by environmental factors (which can include an illness and even sunlight).
What we do know is that a number of factors go into a child’s development of juvenile dermatomyositis, so it’s not caused by just one thing.
Signs and symptoms
What are the symptoms of juvenile dermatomyositis?
The symptoms of juvenile dermatomyositis often appear gradually, although your child may have more acute, or intense, symptoms. Each child may experience symptoms differently, but the most common signs are:
- rash around the eyelids (known as heliotrope rash) and/or knuckles and finger joints (called Gottren’s papules); a rash may also occur on the elbows, knees and ankles
- muscle weakness
- muscle pain and tenderness
- weight loss
- joint pain and inflammation
- calcium deposits under the skin (called calcinosis)
- mouth ulcers
Symptoms may resemble other medical conditions or problems. Always consult your child's physician for a diagnosis.
Q: As a mother, did I cause my child’s juvenile dermatomyositis (JDM) somehow during pregnancy?
A: No. JDM is never caused by something a mother did or didn’t do. We are still unsure what causes JDM, but suspect that there’s a genetic predisposition. If there’s a history of autoimmune conditions in your family, you’re more likely to have a child with an autoimmune disorder. However, in the case of JDM, it also looks as if the condition is brought on by one or more environmental triggers, which can include an illness and even sunlight (which damages the skin).
Q: Could vaccines have caused my child’s juvenile dermatomyositis?
A: A vaccine may trigger your child’s JDM if he was already predisposed to getting the condition, but no one particular vaccine is to blame. In addition, the development of JDM is likely due to more than one environmental trigger—not just a vaccine.
Q: If I have another child, will he or she also develop JDM?
A: The answer is most likely not, although your other children may be at a higher risk of developing some sort of autoimmune disorder. According to studies, there is a 30 percent concordance rate of JDM between identical twins.
Q: Should I give my child a special diet to help with her JDM?
A:No existing data suggests that JDM can be fixed with any sort of special diet—organic, gluten-free or otherwise—or that a certain diet might alleviate your child’s symptoms. We do suggest that patients follow a very balanced diet with enough calcium and vitamin D.
Q: Can my child still play sports?
A: Some children with JDM experience muscle weakness severe enough to prevent them from participating in rigorous physical activity. Whether your child will be affected will depend on how quickly she is treated and how well she responds to treatment. In all cases, we do suggest practicing sun safety, so be sure that your child wears adequate SPF and sun protective clothing whenever there will be sun exposure—especially if she’s playing outdoor sports.
Q: Will my child ever look normal again?
A: Your child may come to us with a rash or other skin manifestations of JDM. However, with treatment, most skin manifestations clear up, and your child will look and act like any other child his age.
Q: Is there a cure for juvenile dermatomyositis?
A: Technically there isn’t a cure for JDM, but with our treatment regimens, we aim to get your child into full remission and off medicines. Most children with autoimmune conditions like JDM will need to see a rheumatologist regularly for review. Once in remission, most kids come back to Children’s or visit a rheumatologist in their area at least once every year.
Q: What should I expect when it comes to my child’s quality of life?
A: This is a question unique to each family. The Children’s Hospital Boston interdisciplinary team welcomes the opportunity to discuss any of your concerns. We expect the vast majority of children will be able to live a full and active life, engaging in all (or most) normal childhood activities. Your child’s experience should be much the same as any other kid’s.