What Is Juvenile Dermatomyositis?

Juvenile dermatomyositis is a rare condition that causes involuntary muscle weakness and affects approximately 3 in 1 million children (3,000 and 5,000 children) in the United States. Females are twice as likely as males to develop this condition, and the most common age range for diagnosis is between 5 and 10, although children as young as 2 and as old as 15 have developed this condition.

This article will explore the different types of dermatomyositis, causes, symptoms, and treatment options.

Types

Dermatomyositis is part of a group of muscle diseases called inflammatory myopathies, which cause involuntary muscle weakness. There are several types of inflammatory myopathies, the causes of which are unknown.

Dermatomyositis is divided into subgroups based on the affected population or symptoms. Examples include:

• Adult dermatomyositis: Occurs in adults
• Juvenile dermatomyositis (JDMS): Occurs in children
• Dermatomyositis sine myositis: Characterized by skin abnormalities without muscle weakness
  

Causes

The cause of juvenile dermatomyositis is unknown, but there are theories that it is an autoimmune disease, suggesting the immune system begins to attack muscle cells and blood vessels, leading to muscle weakness.

Genetics may also play a role, but there have been cases in people with no family history of similar symptoms.

Symptoms

The early symptoms of juvenile dermatomyositis are a purple or dusky red rash, which may develop on the face, eyelids, hands, legs, chest, or back, and can be mistaken for other childhood skin disorders like eczema.

Muscle weakness can occur at the same time as the rash or can take months to develop and typically affects the:

• Back
• Neck
• Shoulders
• Stomach
• Thighs
• Upper arms
  

Weakness in these areas can make it difficult for children affected by this condition to climb stairs, stand from a sitting position, or get in and out of the car.

Muscle weakness doesn't usually come with pain, which helps distinguish it from other conditions with muscle weakness. Other symptoms that can appear with juvenile dermatomyositis include:

• Shortness of breath
• Fatigue
• Depression
• Difficulty swallowing
• Voice changes
• Fever
• Weight loss
• Stomach ulcers or intestinal tears
• Lung problems
• Falling
• Joint stiffness

Diagnosis

Juvenile dermatomyositis is one of many potential diseases in childhood that can appear with muscle weakness and skin rashes. A diagnosis usually begins with a visit to your child's healthcare provider and a physical examination.

There's no specific test to diagnose juvenile dermatomyositis, but a healthcare provider may order the following tests to help rule out other conditions and detect muscle or skin damage.

• Blood testing: Your healthcare provider may look for elevated creatinine kinase levels, which indicates inflammation or muscle damage. Identifying certain enzymes and autoantibodies with a blood test may also be helpful.
• Imaging studies: Magnetic resonance imaging (MRI) is the most common imaging tool to diagnose juvenile dermatomyositis. An MRI can help identify early muscle inflammation and swelling without requiring a biopsy.
• Muscle biopsy: A muscle biopsy is when a small piece of muscle is surgically removed. The muscle tissue is examined under a microscope by a healthcare professional like a pathologist, who will look for signs to help distinguish inflammation from other problems, such as muscular dystrophy.
• Nailfold capillaroscopy: An unusual symptom in active forms of juvenile dermatomyositis is a visible distortion of the nailbeds. During nailfold capillaroscopy, a healthcare provider will examine the nail beds with a lighted magnifier to look for abnormal swelling and blood vessel distortion.
  

Treatments

There are medications and treatments available to manage the symptoms of juvenile dermatomyositis, but they do not cure the disease. In most cases, treatment can help a person experience remission or a break from an active disease state.

Some medications include:

• Corticosteroids (used to suppress autoimmune activity)
• Other immune-suppressing medications like methotrexate
• Intravenous immunoglobulin (antibody injections or shots)
• Medications to reduce the use of steroids like cyclosporine, Protopic (tacrolimus), Rituxan (rituximab), and Plaquenil (hydroxychloroquine)

Your healthcare provider may also recommend lifestyle changes or therapies like:

• Protecting skin from ultraviolet (UVA and UVB) rays
• Stretching
• Physical therapy
• Speech therapy
• Diet changes to accommodate swallowing problems

Coping

Living with chronic disease can be difficult, especially when it limits physical abilities. Parents of children with juvenile dermatomyositis may need to help them with daily activities.

Children can experience stress or depression because of their limitations. Regular exercise and a focus on stress reduction and mental health can help ease the strains of juvenile dermatomyositis.

Prognosis

Juvenile dermatomyositis is not usually cured, but most children can achieve long-term remission with the proper treatment. People with juvenile dermatomyositis should focus on maintaining a healthy diet and regular exercise.

Teachers, family members, and peers should be aware of potential physical limitations with juvenile dermatomyositis, as this disorder may not be evident from outward appearances.

Summary

Juvenile dermatomyositis is a rare condition that is typically found in children between age 5 and 10. It is characterized by a skin rash and muscle weakness. The symptoms of this condition can make it challenging to complete some activities of daily living, like climbing the stairs or getting in and out of the car. Medications and other treatments can help manage the symptoms, but the condition is rarely cured.

A Word From Verywell

Juvenile dermatomyositis can significantly impact physical abilities, but there are treatments to help relieve the symptoms. Most children with this condition achieve long-term remission. Talk to your child's healthcare provider about making a plan with their healthcare team to achieve the best possible outcome and quick remission.