Juvenile myositis (JM) affects those under the age of 18 years.
JM is known for causing muscle inflammation and skin rashes.
These symptoms are the result of ongoinginflammationand swelling of the blood vessels under the skin and in the muscles.
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It also discusses the signs and symptoms, diagnosis, and treatment of juvenile myositis.
Types of Juvenile Myositis
The most common form of JM is juveniledermatomyositis(JDM).
Juvenilepolymyositis(JPM) can also occur in children, but it is much rarer.
Benign acute childhood myositis, also called viral myositis, can also affect children.
It may also affect the blood vessels.
Juvenile polymyositisis also characterized by proximal muscle inflammation leading to weakness.
It may affect multiple body systems, including the digestive tract, heart, and lungs.
It is often seen in children recovering from the flu or another respiratory infection.
What Are the Symptoms of Juvenile Myositis?
The symptoms vary by punch in of juvenile myositis.
Muscle pain and weakness usually start slowly.
The skin rash comes on a few weeks after muscle symptoms start.
The muscle pains and rashes may be non-specific at onset, making early detection of the disease difficult.
Symptoms of JDM can be mild to life-threatening.
Serious symptoms of JDM include joint pain and stiffness, contractures, ulcers, and calcium deposits.
There are also times when a child can experience remissiona period of mild or no symptoms.
Skin Rash
Skin rashes will show up slowly.
The first signs of myositis parents may notice are rashes on their childs eyelids and cheeks.
Rashes may also appear on the nails, elbows, knees, chest, and back.
The muscles gradually become weak and painful.
Common movementslike climbing stairsbecome harder and your child may complain that their muscles hurt.
Your child may also have less energy.
In severe cases of JDM, the muscles responsible for breathing and swallowing may be affected.
That means a child may experience choking while eating or they may easily become short of breath.
JDM can also cause the voice to become hoarse.
Call your childs healthcare provider immediately if you notice any of these severe symptoms.
Ulcers
Skin and gastrointestinal ulcers can develop in JDM, but they do not occur very often.
Severe abdominal pain or bloody stools should also be reported immediately.
Calcium Deposits
Some children with JDM may develop calcium depositsalso called calcium nodulesbelow their skin and in their muscles.
These vary in size and feel like firm, small pebbles under the skin.
These nodules may cause muscle movement problems or break through the skin and drain.
Contact your childs healthcare provider if a nodule becomes sore or begins to drain.
Benign acute childhood myositis is usually not serious.
It often causes mild symptoms and resolves on its own.
What Are the Causes of Juvenile Myositis?
The causes of myositis in children are similar to the causes in adults.
Infections
Viruses, such as the flu and thecommon cold, have long been connected to myositis.
Medications
Many different medications can cause temporary muscle inflammation and damage.
It can also occur as a result of an interaction between two drugs.
Severe myositis resulting from medications is rare.
Inflammation is usually the culprit.
Myositis symptoms after an injury or exercise tend to resolve quickly with rest and time.
How Is Juvenile Myositis Diagnosed?
Physical Examination
The pediatric healthcare provider will examine the childs skin and test their muscle strength.
They will want to know if certain activities are difficult because of muscle weakness.
This would include activities like walking up steps and lifting the arms over the head.
An electromyogram (EMG) may be done to look for any nerve or muscle damage.
Another important modality is an FDG PET CT, which uses nuclear imagining techniques.
Muscle and skin biopsies: A muscle biopsy is a definitive way to diagnose all types of myositis disease.
How Is Juvenile Myositis Treated?
There is no cure for JM, but the condition is treatable.
Treatments can reduce or eliminate symptoms and help your child to lead an active and healthy life.
Another goal is to help your child learn to live with JM.
Your childs treating healthcare provider will work with your family to find the best plan for your child.
Treatment will include medication, physical therapy, and education.
Steroids can be given orally, by injection, or intravenously (directly into a vein).
Dosage and duration of treatment depend on the severity of symptoms.
They may be given alone or with hydroxychloroquine (ananti-malaria drug) and mycophenolate mofetil.
Other medications: Another medicine used to treat JM includes ananti-TNF biologic drug, rituximab.
Physical Therapy
Physical therapyand physical activity are important for children with JM.
They can help a child to maintain and increase muscle strength and flexibility.
This prevents muscle wasting and stiffness.
You should applysunscreento your childs skin and have them wear protective clothing when outdoors.
Education for the family also includes ways to keep your child active at home and school.
Discussions with a dietitian about healthy and safe eating are also vital because JM can affect chewing and swallowing.
However, no other treatment is necessary for the myositis because symptoms will improve within a few days.
Coping and Outlook
Children with JM can live life as normally as possible.
They can attend school, play sports, and participate in family activities.
Your child can follow a standard, healthy diet.
How Long Can Myositis Last?
Juvenile myositis is a chronic condition, but it affects all children differently.
Other children may require life-long treatment to manage myositis symptoms.
The most important thing is for your child to take all their medications and complete physical therapy.
And most childreneven those that face bigger challengeswill grow up to lead full and active lives.
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