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  • Writer's pictureThe Rare360 Editorial Team

Beyond the Skin and Muscles: Understanding Dermatomyositis


A doctor holding hands with her patient during a consultation.

Living with a rare disease brings its own set of hurdles, and Dermatomyositis is no exception. This rare disorder not only affects muscles but also leaves its mark on the skin. It is a type of inflammatory myopathy that intricately weaves a tale of inflammation and degeneration, setting it apart from other muscle disorders by leaving its imprint on the skin as well.


While the precise origins of Dermatomyositis remain shrouded in mystery, it is believed to kick in when the immune system mistakenly attacks healthy tissues - an autoimmune response. Genetics and various environmental factors like infections, sun exposure, certain medications, and smoking may also cause this complex disorder.


This condition, resilient and defiant, knows no age bounds, making its presence felt across the spectrum of life. However, the symphony of symptoms most commonly harmonizes between the ages of 40 to 60, with women bearing a disproportionately higher burden than men. The intertwining of Dermatomyositis with connective tissue disorders, such as lupus or rheumatoid arthritis, adds yet another layer to the narrative, showcasing the interconnected nature of this rare disorder.


With an estimated incidence of 9.63 cases per million individuals, this rarity echoes not only in the adult world but also resonates with the younger generation. In children, the onset typically unfolds between the tender ages of five to 15 years, with juvenile dermatomyositis affecting a small but significant three in 1,000,000 children. And as the gender narrative unfolds, females emerge as the more frequent companions in the journey through dermatomyositis, their experiences doubling in frequency compared to their male counterparts.

 

Comprehensive Symptom Profile of Dermatomyositis

While skin manifestations often precede or coincide with muscle involvement, individuals may experience a diverse array of symptoms. Muscle disease may occur concurrently, may precede the skin disease, or may follow the skin disease by weeks to years. Here is a breakdown of the symptoms associated with dermatomyositis:


Skin Manifestations:

  • Red or Purple Rash: A distinctive rash appears on sun-exposed areas, potentially causing pain or itching.

  • Heliotrope Swelling: Upper eyelids may exhibit red or purple swelling known as heliotrope.

  • Gottron's Papules: Red or purple spots manifest on knuckles, elbows, knees, and toes in the form of Gottron's papules.

  • Scaly, Rough Skin: Skin becomes scaly, rough, and dry, potentially leading to hair thinning.

  • Fingernail Area Inflammation: Swollen, red areas may surround the fingernails.


Muscle Involvement:

  • Muscle Weakness: Difficulty rising from a chair, sitting upright, or getting out of bed due to muscle weakness. Muscle weakness may affect the neck, hip, back, and shoulders.

  • Calcinosis: Hard lumps under the skin may develop due to calcium deposits.

  • Esophageal Involvement: Muscles in the esophagus may weaken, leading to difficulty swallowing, weight loss, and malnutrition.

  • Aspiration Risk: Difficulty swallowing may cause inhalation of food, liquids, or saliva into the lungs.

  • Breathing Problems: Chest muscle involvement can result in shortness of breath.


Systemic Manifestations:

Systemic manifestations that may occur include the following:

  • General Systemic Disturbances: Fever, arthralgia, malaise, and chronic tiredness may occur.

  • Cardiac Issues: Atrioventricular defects, tachyarrhythmias, and dilated cardiomyopathies may occur.

  • Gastrointestinal Complications: Ulcers and infections may affect the gastrointestinal tract, particularly in children.

  • Pulmonary Involvement: Weakness of thoracic muscles and interstitial lung disease may lead to pulmonary issues.

  • Subcutaneous Calcification: Calcium deposits may cause joint contractures, particularly in children.

  • Motor Issues in Children: A tiptoe gait may develop in early childhood.

  • Malignancy Risk: Adult patients may face an increased risk of commonly associated cancers include breast, melanoma, colon, ovarian, nasopharyngeal, and non-Hodgkin’s lymphoma.


Associated Conditions and Risks in Dermatomyositis

Dermatomyositis is often associated with other conditions or may increase the risk of developing them, including:

  • Raynaud's phenomenon: This condition manifests as pale discoloration of fingers, toes, cheeks, nose, and ears when exposed to cold temperatures.

  • Cardiovascular disease: Heart muscle inflammation can result from dermatomyositis, potentially leading to congestive heart failure and heart rhythm abnormalities in a small percentage of individuals.

  • Lung disease: Dermatomyositis can lead to interstitial lung disease, a group of disorders characterized by scarring of lung tissue, causing stiffness and reduced elasticity. Symptoms may include a dry cough and shortness of breath.

  • Cancer: About 15% of individuals with dermatomyositis may develop cancer later in life. The risk of cancer tends to stabilize approximately three years after a dermatomyositis diagnosis. Common types of cancer associated with dermatomyositis include ovarian cancer, lung cancer, lymphoma, breast cancer, and colon cancer.

  • Other connective tissue diseases: Dermatomyositis may coexist with conditions such as rheumatoid arthritis, lupus, Sjogren’s syndrome, and scleroderma.

 

Diagnostic Journey in Dermatomyositis

Diagnosing dermatomyositis can be challenging due to its rarity. A careful history followed by a thorough physical exam will be necessary for a specialist such as a pulmonologist or rheumatologist to ascertain a diagnosis. The diagnostic journey typically unfolds as follows:


  • Initial Assessment:

    • A detailed medical history is obtained, focusing on symptoms such as rash, muscle pain, and pulmonary issues.

    • A thorough physical examination is conducted to identify characteristic signs, including skin rash and muscle weakness.

  • Diagnostic Tests:

    • Blood tests. These are done to look for signs of muscle inflammation. They also check for abnormal proteins that form in autoimmune disease. The most common blood tests include muscle enzyme creatine kinase and the antinuclear antibody. If you have elevated levels of muscle enzymes that can indicate muscle damage. A blood test can also detect autoantibodies associated with different symptoms of dermatomyositis, which can help in determining the best option for medication and treatment.

    • Chest X-ray: This simple imaging test can check for signs of the type of lung damage that sometimes occurs with dermatomyositis.

    • Electromyogram (EMG): This test may be done to find abnormal electrical activity in affected muscles. A doctor with specialized training inserts a thin needle electrode through the skin into the muscle to be tested. Electrical activity is measured as you relax or tighten the muscle, and changes in the pattern of electrical activity can confirm a muscle disease. The test can also help pinpoint the affected muscles.

    • MRI (Magnetic Resonance Imaging): This imaging technique generates detailed cross-sectional images of muscles to detect inflammation. Unlike a muscle biopsy, MRI can assess inflammation across a broader muscle area.

    • Biopsy: Small samples of skin or muscle tissue are taken for microscopic examination. A skin biopsy aids in confirming dermatomyositis diagnosis, while a muscle biopsy may reveal muscle inflammation or other abnormalities.


This diagnostic approach is crucial for differentiating dermatomyositis from other conditions and understanding the extent of organ involvement. Collaboration with specialists and a combination of these tests aids in accurate diagnosis and guides the development of a tailored treatment plan for individuals with dermatomyositis.


Treatment Strategies for Managing Dermatomyositis

There is currently no cure for dermatomyositis, but treatment options aim to alleviate symptoms and improve both skin condition and muscle strength and function. These treatments encompass various approaches:


  • Medications

    • Corticosteroids: Rapid symptom control can be achieved with drugs like prednisone (Rayos). However, prolonged usage may lead to severe side effects. Doctors typically begin with a high dose to manage symptoms and gradually taper it as improvement occurs.

    • Corticosteroid-sparing agents: These medications, such as azathioprine (Azasan, Imuran) and methotrexate (Trexall), are used alongside corticosteroids to reduce dosage and associated side effects. Mycophenolate mofetil (Cellcept) may also be prescribed, especially when lung involvement is present.

    • Rituximab (Rituxan): Although more commonly used for rheumatoid arthritis, rituximab can be considered if initial treatments prove ineffective.

    • Antimalarial medications: Hydroxychloroquine (Plaquenil) may be prescribed to address persistent rashes.

    • Sunscreens: Protecting the skin from sun exposure with sunscreen and appropriate clothing is crucial for managing dermatomyositis-related rashes.

  • Therapy

    • Physical therapy: Exercises designed to maintain and enhance strength and flexibility are recommended. These exercises can aid in muscle repair and improve overall muscle function. Orthotics or assistive devices may also be utilized.

    • Speech therapy: If swallowing muscles are affected, speech therapy can provide strategies to manage swallowing difficulties and strengthen throat muscles.

  • Surgical and other procedures

    • Intravenous immunoglobulin (IVIg): IVIG, a blood product containing healthy antibodies from multiple donors, can neutralize the harmful antibodies attacking muscles and skin in dermatomyositis. Administered intravenously, IVIG treatments may require regular repetition for sustained effects.

    • Surgery: Surgical removal of painful calcium deposits and prevention of recurrent skin infections may be considered in some cases.

Additionally, the U.S. Food & Drug Administration (FDA) approved a treatment for adults with dermatomyositis on July 15, 2021. This approval pertained to a 10% solution of human intravenous immunoglobulin (IVIG), known as Octagam 10%. This treatment was previously approved by the FDA for chronic immune thrombocytopenic purpura.


Conclusion

In conclusion, dermatomyositis presents a complex and challenging journey for those affected, characterized by a diverse array of symptoms and potential complications. However, early diagnosis and prompt treatment are crucial in managing the condition and improving outcomes. While some cases may enter remission with appropriate therapy, others necessitate long-term management to alleviate symptoms and prevent complications.


Tragically, dermatomyositis can significantly impact quality of life, with two-thirds of individuals experiencing physical disability due to muscle damage. Additionally, it's important to acknowledge the severity of the condition, as approximately 5% of those diagnosed with dermatomyositis face fatal outcomes, particularly within the first year of diagnosis. Nevertheless, there is hope, as about 20% of individuals with dermatomyositis may achieve long-term remission with appropriate treatment and management strategies.


In light of these challenges, ongoing research and medical advancements are essential in improving the prognosis and quality of life for individuals living with dermatomyositis. With continued efforts in early detection, personalized treatment approaches, and supportive care, we strive towards better outcomes and a brighter future for those affected by this complex autoimmune disorder.


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