(Dermatomyositis) It's hard to even raise your arms... Is weakened neck and shoulder muscles a sign of a serious illness?

Mr. A, a 46-year-old office worker, habitually bought and drank juice every morning on his way to work. He even frequently substituted rice for dairy products like milk. Then, one day, he suddenly felt so weak in his neck and shoulder muscles that he could barely comb his hair. Then, a red rash began to form on his knuckles. Startled, he went to the hospital and was diagnosed with dermatomyositis. Dermatomyositis is an incurable autoimmune disease, and it's highly likely to coexist with cancer, making a thorough diagnosis crucial.

 

◇ Muscle weakness and skin rashes should not be taken lightly.

 

Dermatomyositis is an autoimmune disease that causes inflammation of skeletal muscles. It's a rare condition, occurring in 5 to 10 people per 100,000, but can strike suddenly without warning. The main symptoms of dermatomyositis are muscle weakness and a skin rash. Muscle weakness is particularly evident in the neck, shoulders, pelvis, and thighs, making everyday tasks like climbing stairs, combing hair, washing one's face, and standing difficult.

The most representative skin rash is the 'heliotrope rash', which is a purple rash around the eyelids. Other symptoms include ▲'Gothron's spots', a rough red rash on the elbows, knees, wrists, and finger joints; ▲'Shoulder sign', a red rash on the neck, chest, back, and shoulders; ▲'Machine's hand', which causes the palms and sides of the fingers to become rough and cracked; ▲'photosensitivity', which makes the skin sensitive to sunlight; and ▲'calcium deposition', which causes calcium to be deposited under the skin. Professor Jeong Seong-su of the Rheumatology Department at Soonchunhyang University Hospital said, "Severe inflammatory symptoms can appear in the lungs, cardiovascular system, and gastrointestinal tract," and "autoimmune diseases such as lupus, scleroderma, and rheumatoid arthritis can accompany it."

The exact cause of dermatomyositis remains unknown. Autoimmune diseases are typically associated with genetic predisposition, immune system abnormalities, environmental factors, and cancer. Among environmental factors, an imbalance in gastrointestinal bacteria is known to trigger immune system dysfunction, leading to chronic inflammation.

 

Professor Jeong said, “Since 70-80% of our body’s immune cells are distributed in the gastrointestinal tract, repeated, bad eating habits over a long period of time can cause an imbalance in the gastrointestinal bacteria, which can affect the development of dermatomyositis.” He also said, “In addition, fatigue can worsen dermatomyositis symptoms, and it is also necessary to block UV rays, minimize sunlight exposure, moisturize, and maintain indoor humidity to avoid skin irritation.”

◇Cure is difficult, but treatment options such as biological agents are increasing.

 

Diagnosis of dermatomyositis is based on symptoms such as skin rash and muscle weakness, including blood tests to determine muscle enzyme levels and autoantibodies, electromyography, and imaging tests such as MRI. Muscle and skin biopsies may be performed if necessary. Additional testing may be performed to rule out other causes, such as autoimmune diseases, infections, and cancer. Differentiating dermatomyositis from other muscle-related conditions, such as muscular dystrophy, systemic sclerosis, lupus, Lyme disease, and infectious myositis, is particularly important.

 

Treatment focuses on reducing inflammation and managing symptoms, depending on the patient's condition. Pharmacological treatment includes corticosteroids to reduce inflammation. For patients resistant to steroids, immunosuppressants such as methotrexate, azathioprine, and mycophenolate mofetil are used. Recently, biologic agents such as rituximab have also been used for patients who do not respond to conventional treatments.

Antimalarial medications may be used to manage skin symptoms, and physical therapy is recommended to maintain and improve muscle strength.

Professor Jeong said, “Since immunosuppressants can make patients more susceptible to infection, thorough infection prevention measures are necessary,” and “regular monitoring is essential to check for drug side effects and disease activity.”

 

◇Not contagious, but...high risk of cancer coexistence

 

Because dermatomyositis is characterized by a skin rash, some patients often wonder if it's contagious. Dermatomyositis is an autoimmune disease, meaning the immune system attacks the body, so it's not contagious. However, patients with dermatomyositis have a relatively high risk of developing cancer. Especially after age 50, certain cancers, such as ovarian, lung, stomach, and pancreatic cancers, can coexist with the disease. Therefore, if diagnosed with dermatomyositis, regular cancer screening may be necessary.

 

Professor Jeong Seong-su said, “While a skin rash appears as one of the initial symptoms in many patients with dermatomyositis, some patients are first diagnosed with symptoms such as muscle weakness or fatigue.” He added, “Early diagnosis and active treatment have a positive effect on the prognosis, so if you have any suspicious symptoms, you should immediately receive a thorough examination at a hospital to receive an accurate diagnosis.”

 

 

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This is my first time hearing about dermatomyositis.

I'll have to take a closer look.

 

Fortunately, it is not contagious,

It is related to immunity,

 

Even looking at the self-diagnosis chart, it seems a bit difficult.

 

I'll have to check first to see if there are any red spots on the skin.