Juvenile Dermatomyositis

Juvenile Dermatomyositis

Overview

Juvenile dermatomyositis (JDM) causes inflammation in your skin, blood vessels and muscles. Common symptoms are muscle weakness and a skin rash. People start experiencing these symptoms during childhood.

Juvenile dermatomyositis can cause muscle weakness that limits movements. Your child may have trouble standing up, climbing stairs, running or even brushing their hair. A diagnosis of any condition that limits your child’s daily activities can be disheartening. But treatment for JDM can manage symptoms effectively and improve your child’s quality of life.

Symptoms

Before diagnosis, you may notice early signs of juvenile dermatomyositis in your child, like:

Fatigue.

Fever.

Joint stiffness or swelling.

Lack of hunger.

Muscle pain during usual activities.

Muscles that feel tender when touched.

Unexplained weight loss.

Weakness.

Rash on the face or hands, or sensitivity to the sun.

JDM tends to cause two ongoing symptoms: a skin rash and muscle weakness.

Skin rash

Children with juvenile dermatomyositis often have a skin rash. It may start as reddish or purplish cheeks and eyelids. Your child may have puffy eyelids that get misdiagnosed as allergies.

Over time, your child may develop inflamed patches of dry skin or bumps over their knuckles, knees or elbows. These patches may look similar to eczema or psoriasis. They often worsen after exposure to sunlight.

Muscle weakness

Your child may complain of soreness or weakness affecting the muscles in their:

Belly.

Hips.

Neck.

Shoulders.

Upper arms and legs.

This muscle weakness can make it challenging to complete everyday movements like getting up from the floor or climbing stairs. In severe cases, JDM may affect children’s breathing or swallowing muscles. This can cause symptoms like:

Easily choking on food.

Faint or hoarse voice.

Shortness of breath (dyspnea).

Complications

Without treatment, juvenile dermatomyositis can cause:

Calcium deposits, firm spots under their skin that can limit muscle movements.

Muscle contractures, shortened muscles that cause bent joints.

Ulcers in their skin or gastrointestinal (GI) tract.

Severe weakness when moving, swallowing or breathing.

Death. Before treatment was available, about 1 in 3 children would die from juvenile dermatomyositis. Now, more than 98% are alive 5 years after diagnosis

Causes

Juvenile dermatomyositis occurs when your immune system attacks your tissues and cells. These types of conditions are called autoimmune diseases.

Experts don’t know exactly why the immune system begins this attack. Researchers think it may occur when your body fights infection but doesn’t stop the immune response after the virus is gone. They also think there could be a genetic component.

Diagnosis 

To diagnose JDM, your child’s provider physically examines them to look for signs like a skin rash. They also test your child’s muscle strength and ask about their symptoms.

They may also use several tests, including:

Blood tests: There’s no single blood test that diagnoses JDM. But blood tests can check for high levels of inflammation and elevated levels of muscle enzymes that could point to JDM. Providers may also use blood tests to look for specific proteins — called autoantibodies — that often occur when children have juvenile dermatomyositis.

Electromyography (EMG): Your child’s healthcare provider inserts small needle electrodes into specific muscles. These needles record the electrical activity in their muscles. Your child may need to contract or relax certain muscles or change positions throughout the test.

MRI (magnetic resonance imaging): An MRI uses powerful magnets and radio waves to create a detailed image of the inside of your child’s body. MRIs are helpful tests for diagnosing JDM because they can spot subtle changes in muscle inflammation and swelling.

Muscle biopsy: Your child’s provider performs a minor procedure to remove a small piece of muscle tissue. The tissue sample goes to a lab for analysis under a microscope. This test can help detect muscle inflammation. It also helps providers understand whether the inflammation is caused by JDM or another type of muscle disease, like muscular dystrophy.

Nailfold capillaroscopy: The provider uses a special tool with a light and magnifier to examine your child’s nailbeds. This tool can reveal blood vessel swelling that’s common in children with juvenile dermatomyositis.

Treatment

Juvenile dermatomyositis treatment focuses on reducing inflammation and improving your child’s quality of life. While most children deal with JDM for several years, treatment can significantly lessen their symptoms. Many children experience long periods of remission after treatment, where they go several months or even years without any symptoms and may not have problems in adulthood.

Juvenile dermatomyositis medications

Most children with juvenile dermatomyositis take medication to decrease inflammation. Common medication options include:

Corticosteroids: These medicines are usually a first-line treatment for JDM because they quickly reduce inflammation. They also limit antibody production, so your child’s immune system stops attacking their tissues. Children may start with a high dose of intravenous (IV, through a vein) or oral (by mouth) corticosteroids. Doctors reduce the dose as symptoms improve.

Hydroxychloroquine: Children with a skin rash may take hydroxychloroquine to manage symptoms. They usually take it by mouth once a day.

Intravenous immunoglobulin (IVIG): Your child receives an IV line with purified antibodies from blood donors. IVIG can help block harmful antibodies and reduce the immune system response that’s causing inflammation.

Methotrexate: Nearly all children with JDM take methotrexate, usually at the same time as, or shortly after, taking a corticosteroid. Methotrexate helps suppress their immune system and can decrease the amount of steroids they need.

Other corticosteroid-sparing agents: Depending on their symptoms, children may take other drugs such as cyclosporine, rituximab or mycophenolate mofetil. These medications are typically reserved for more severe cases when other medications don’t reduce symptoms.

Juvenile dermatomyositis lifestyle changes and therapies

Several lifestyle changes and noninvasive therapies also help to manage JDM symptoms, including:

Diet changes: Eating plenty of fruits, vegetables, lean protein, healthy fats and whole grains can help lower inflammation. Your child may need more personalized nutrition support if they have swallowing problems related to JDM.

Physical therapy: A physical therapist gives your child exercises to improve muscle strength and prevent stiffness and pain. The physical therapist may also offer stretches or splints that improve flexibility and stability.

Speech therapy: A speech therapist can help your child learn to compensate if they have weakened swallowing or breathing muscles. They may also recommend safer foods or tongue and chin positions that lower the risk of choking.

Sun protection: Adequate protection from ultraviolet (UV) rays can help reduce rashes. Children should wear broad-spectrum sunscreen with an SPF of at least 30 every day. They should wear hats, sunglasses and sun-protective clothing. You may also keep your child indoors or seek shade when the sun’s UV rays are strongest, between 10 a.m. and 4 p.m.

Type of Doctor Department : A pediatric rheumatologist