About Juvenile Dermatomyositis

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What is Juvenile Dermatomyositis?

Juvenile dermatomyositis (JDMS) is an inflammatory autoimmune disease affecting approximately three in one million children1.

Autoimmune diseases generally occur when the body's immune system begins to malfunction and attacks healthy tissue in various parts of the body, causing inflammation which then results in damage to tissues.
  • Juvenile dermatomyositis is a part of a family of conditions called "myos-itis" (translated, it literally means "muscle-inflammation”).
  • In dermatomyositis, muscle and skin are affected, but the joints, lungs, heart, and intestinal tract may also be involved2.
While the cause of juvenile dermatomyositis remains unknown, some researchers believe it may be a combination of inherited susceptibility and external triggers. To date, there is no known cure for the disease, but it is treatable.

Who can develop juvenile dermatomyositis?

Juvenile dermatomyositis affects girls and boys in equal numbers. The average age of onset is seven years of age1.

The main symptoms of juvenile dermatomyositis

Because some symptoms of dermatomyositis are similar to those of other diseases and because it is rare, it can be difficult for physicians to make the diagnosis. Often, the characteristic skin rashes are first misdiagnosed as eczema or psoriasis. Muscle pain can be mistaken for growing pains or overuse, and muscle weakness can be confused with laziness or sleepiness.

There are several hallmark symptoms of juvenile dermatomyositis that may be present at the time of diagnosis. These warning signs can include2:
  • Rash-including red facial rash, rash on arms and legs, scaly patches on elbows and knees, and hardened patches on fingers at the knuckles
  • Muscle weakness
  • Muscle pain
  • Fever
  • Fatigue
  • Difficulty swallowing
  • Softer or hoarse voice
  • Joint pain and swelling
Getting a diagnosis of juvenile dermatomyositis

Doctors may order several different types of tests to confirm a possible diagnosis of juvenile dermatomyositis. Tests may include3:
  • Blood tests
  • Urine analysis
  • Muscle strength and function tests
  • Muscle imaging tests, including magnetic resonance imaging (MRI) and ultrasound scans, and less commonly, computed tomography (CT) scan
  • Muscle biopsy
  • Electromyography, a test in which a small needle is placed into the muscle, electrically stimulating the muscle, and measuring the response
Once a diagnosis of juvenile dermatomyositis has been made, the child will usually be sent to a pediatric rheumatologist—a doctor who specializes in treating childhood autoimmune diseases related to the joints and muscles. Pediatric rheumatologists have at least five years of extra training in addition to regular medical schooling. They work in a multidisciplinary team that includes nurses, physiotherapists and occupational therapists. Other specialists usually involved in treating a child with juvenile dermatomyositis may include pediatric dermatologists to treat the skin problems associated with the disease.

Treatment of juvenile dermatomyositis

While there is no known cure for juvenile dermatomyositis, treatment advances are allowing more children to live healthy and active lives. A well-rounded treatment plan for juvenile dermatomyositis includes medication, education, physiotherapy and occupational therapy, and a healthy diet.


The most common medications used to treat the inflammation in juvenile dermatomyositis are oral or intravenous (“IV”) steroids, like prednisone and methylprednisolone, which work to calm down the overactive immune system and decrease inflammation. Methotrexate, another medication used to decrease inflammation, is often also used in combination with prednisone.

Intravenous immunoglobulin, a drug prepared from human blood, also appears to be of benefit in treating severe skin involvement and may be added onto treatment with steroids and methotrexate.

Many parents of children with juvenile dermatomyositis feel conflicted when giving strong medications in high doses to their children. For that reason, education is such a critical part of a treatment plan for juvenile dermatomyositis. Like many inflammatory arthritis diseases, early aggressive treatment is vital. Parents/guardians who have received all of the necessary information are more likely to be able to help create and implement a well-rounded, effective treatment plan. Children who are treated quickly and effectively have the very best chance of full recovery.

Physiotherapy and occupational therapy3,5

Physiotherapy and occupational therapy can help to prevent muscle tightening and damage. After the disease is controlled, physiotherapy may be helpful in regaining strength and range of motion. In almost all cases, children are encouraged to return to their regular physical activities as soon as they are able. Occupational therapy may help to adapt everyday activities to be more accessible for children living with juvenile dermatomyositis and help reduce fatigue.

Sun protection5

Sunscreen is recommended for children with juvenile dermatomyositis, as the rash can become more active with sun exposure. Sunscreen with SPF 30 or higher is usually recommended. Hats and long-sleeved clothing can also serve as sun protection.


Nutrition is also an important component of treatment for any disease, and this is especially true for one requiring steroid treatment. Children with juvenile dermatomyositis should eat a diet low in sodium and high in calcium and vitamin D to help prevent the brittle bones that are a potential side-effect of steroid treatment.

Key take-aways

  • Getting a timely diagnosis and starting treatment are vital. If you think your child is experiencing symptoms of JDMS, speak with a paediatrician today for more information.
  • A successful treatment plan requires informed families and their full and active participation, but remission is possible.
  • Lifestyle adaptations for juvenile dermatomyositis include proper sun protection and eating food low in sodium and high in calcium and vitamin D when using a steroid treatment.
Thank you to Dr. Mercedes Chan, pediatric rheumatologist, BC Children’s Hospital, for her medical review of the content on this page.

1Mendez et al. (2003). US incidence of juvenile dermatomyositis, 1995–1998: results from the National Institute of Arthritis and Musculoskeletal and Skin Diseases registry.
2American College of Rheumatology
3Pachman et al. (2021). Juvenile Dermatomyositis: New Clues to Diagnosis and Therapy.
4Bellutti Enders et al. (2017). Consensus-based recommendations for the management of juvenile dermatomyositis.
5Huber (2018). Update on the clinical management of juvenile dermatomyositis.
6The Myositis Association website