April 18, 2023

Dermatomyositis: What It Is and How It Affects the Skin

Dermatomyositis is one example of inflammatory myopathies, a group of rare diseases characterized by inflammation and weakness of the muscles.

Anyone can develop the disorder. However, it is most prevalent in women, and most patients are between 40 and 60 when they are diagnosed. Fevers, rashes, weakness, and weight loss are common symptoms in the early stages of the disorder. Elevated creatinine kinase (CK) is often noted in blood work, indicating damage to skeletal muscles.

Weakness of the skeletal muscles closest to the trunk, such as those in the hips, thighs, shoulders, upper arms and neck, is the most common symptom of dermatomyositis. Both the left and right sides of the body are affected, and weakness tends to worsen gradually. Over time, the distal muscles can be affected.

These muscles can become tender or sore, and weakness can eventually lead to difficulty performing tasks such as lifting the arms or climbing stairs. For long-term patients, this can cause a loss of muscle bulk, or atrophy. In particularly severe cases, contractures, in which joints become permanently fixed in a bent position, can occur.

Dermatomyositis can also affect the muscles involved in singing and speech, making both more difficult–especially in more severe cases. Dysphagia, or difficulty swallowing, is widely noted. The heart muscle can also be affected.

The disorder is often misdiagnosed as systemic lupus erythematous (SLE), and to complicate matters, the two disorders are known to occur together. It is also associated with certain cancers (breast, nasopharyngeal, stomach, ovarian, lung, pancreatic, colorectal, melanoma, and non-Hodgkin’s lymphoma). These cancers are usually diagnosed within the first two years after the onset of dermatomyositis symptoms.

Dermatomyositis: A Changeable Outlook

Dermatomyositis is chronic and incurable, and while the prognosis for most patients is quite good, for some it is progressive–as seems to have been the case with Maria Callas. The disorder could have contributed to her heart attack directly through inflammation of the heart muscle.

It could also have contributed indirectly; vasculitis, or inflammation of the blood vessels, is a common complication of dermatomyositis. The damage it does to the blood vessels could obstruct blood flow to the heart. Interstitial lung disease could have contributed; so too could long-term use of systemic steroids, which would have been the primary treatment available to Callas.

So What Is Dermatomyositis?

We know more about dermatomyositis today than we ever did, but it remains a mystery in many ways. Is it an autoimmune disorder, or is it caused by an autoimmune disorder? Is it caused by cancer, or does the disorder itself predispose sufferers to certain cancers? Is it triggered by viral infections? Does heredity play a role?

While there is no agreement about the immunology of dermatomyositis, it is increasingly thought to be an autoimmune disorder in which antibodies attack the small blood vessels (microvasculature) that supply the muscles.

A strong correlation exists between infection with the Epstein-Barr virus and the development of juvenile dermatomyositis; another correlation has been found between the disorder and infection with coxsackievirus (which causes hand, foot, and mouth disease).

Human immunodeficiency virus (HIV), toxoplasma gondii, and the Borrelia bacterium have also been implicated as possible triggers.

Complications, Prognosis, and Duration of Symptoms

Mortality rates for the disorder are low, with a 95 percent five-year survival rate.

Dermatomyositis patients can experience a wide variety of complications, depending on factors such as underlying health conditions, severity of the disorder, and how long they have had the disorder.

We briefly mentioned Interstitial lung disease; this common complication involves inflammation and scarring of lung tissues, which can negatively affect respiration. Vasculitis, or inflammation of blood vessels, is another common complication

Calcinosis cutis, or calcification of soft tissues, is another potential complication.This is more often found in children who are diagnosed with dermatomyositis. These deposits can sometimes be felt as small, hard bumps beneath the skin.

For some, dermatomyositis symptoms improve after a period of time and do not return to trouble them. Others experience remissions of symptoms interrupted by periodic flares throughout their lives. Still others will experience severe symptoms that persist and progress without remission.

For a significant number of people, a rash is the first symptom that brings them to the doctor.

The so-called “heliotrope rash”----a mottled, dusky-red or violet rash around the eyes–is a textbook symptom of early dermatomyositis. Swelling of the eyelids is common with this rash, and it can be itchy and painful. Similar rashes can also occur on the scalp, cheeks, nose, back, upper chest, elbows, and knees. The rash is often worse on skin that has been exposed to the sun, and sun exposure tends to worsen the rash for many.

Over the upper chest and upper back, there may also be a symmetric persistent red rash. This red rash can develop a mottled appearance with small white areas called poikiloderma. Some DM patients temporarily experience small areas of skin necrosis and crusting and bleeding, secondary to a unique lymphocytic vasculitis.

Gottron papules are another dermatological sign of dermatomyositis. They present as red, scaly patches, and they’re primarily seen between the knuckles and the areas around the fingernails–including the cuticles. They can also develop on the elbows and knees. They are itchy, often painful, and they sometimes bleed. Like the heliotrope rash, they are exacerbated by sunlight.

Treatment For Dermatomyositis

Dermatomyositis is an incurable, chronic disorder; treatment consists of treating muscle weakness, interrupting or slowing down the inflammatory process, and managing symptoms, and preventing major calcinosis. Some cases remain mild, and others are very severe and very refractory to most therapies. Evaluation at a University referral Medical center, seeing both Rheumatology and Dermatology departments is important. Powerful medications that deplete the antibody attack should be considered along with targeted therapy for cytokine signaling.

Patients are usually given high doses of prednisolone until CK levels are normal and muscle strength improves, after which steroid treatment is tapered down gradually. Immunosuppressant drugs such as Azathioprine and methotrexate are often prescribed concurrently.

If symptoms are resistant to steroids and azathioprine/methotrexate, drugs such as rituximab, mycophenolate mofetil, calcineurin inhibitors, intravenous immunoglobulin (IVIG), and cyclophosphamide will be considered.

Calcium deposits are usually removed surgically, though biologic and targeted therapies (such as infliximab and tofacitinib) can be enlisted to inhibit calcinosis.

How to Treat Dermatomyositis Rash

Protecting the skin from sunlight is one of the first and most important steps dermatomyositis patients must take. Sunlight should be avoided where possible. Sun-protective clothes, including hats, should be worn when it cannot. Daily application of a sunscreen with a sun protective factor (SPF) of 50 or higher is vital. Adding a tinted mineral sunscreen is even better.

Systemic drugs are often necessary to control skin involvement, the most common of which are methotrexate and the antimalarial drug hydroxychloroquine. The systemic steroids prescribed to manage inflammation of the muscles are not effective treatments for the rashes associated with dermatomyositis.

Oral antihistamines such as diphenhydramine and cetirizine are sometimes used to manage itching, as are amitriptyline and gabapentin.

Topical treatments can include corticosteroid creams and calcineurin inhibitors, as well as over-the-counter menthol or camphor ointments.

Prescription treatments are important, but when symptoms such as redness, itching, and swelling break through, SmartLotionⓇ is an excellent adjunctive treatment.

SmartLotionⓇ has a unique formula that allows it to work safely with most prescription treatment with little risk of adverse effects. Its prebiotic formula supports the skin’s barrier function and allows a very small amount of hydrocortisone to often help without using stronger topical steroids.

SmartLotionⓇ has a unique formula that allows it to work safely with most prescription treatment with little risk of adverse effects. Its prebiotic formula supports the skin’s barrier function and allows a very small amount of hydrocortisone to work quickly and effectively with no risk of refractory symptoms.

SmartLotionⓇ was formulated by Steve Harlan, MD, a board-certified dermatologist who wanted a safe and efficacious treatment for his patients with chronic, long-term skin disorders regardless of their application needs. He stresses that SmartLotionⓇ is not a cure; there is no quick fix for dermatomyositis rash, but it can often replace or substitute for the stronger topical steroids, with your Dermatology provider’s supervision.

Instead, he focuses on the long-term maintenance strategy. For combatting the redness of dermatomyositis rashes on the face, Dr. Harlan has his patients apply SmartLotionⓇ two times daily for two weeks, then once a day for at least another two weeks, and sees them every 3 months.

For dermatomyositis itching and rashes on the body, he has patients apply SmartLotionⓇ eczema cream four times daily for four weeks, then twice a day, and he sees them every 3 months.

After this, he advises them to use SmartLotionⓇ as needed to manage symptoms. Used under a physician’s guidance, SmartLotionⓇ is a safe way for patients to take control of the chronic symptoms of dermatomyositis.

For Gottron’s papules, and the body rashes of DM, moisturization is vital. Any cracking or bleeding should be kept clean. Apply a small amount of ointment such as AquaphorⓇ, Vaseline Petroleum JellyⓇ, or CeraVe Healing OintmentⓇ to crusted areas. Apply SmartLotionⓇ after applying moisturizer; moisturize regularly throughout the day.

A Bright Future

Dermatomyositis demands a lot from both patients and doctors, it can be debilitating and dangerous. Today, we have access to treatments that people and their doctors could not have dreamed of; with a combination of good self-care, appropriate treatment–including SmartLotionⓇ–and well-experienced physicians, dermatomyositis patients can take some control in managing their symptoms and live fuller lives.

Cee Van

Medical Writer

HarlanMD.com

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