Dermatomyositis: Myositis and the Skin

Dermatomyositis: the Skin Perspective

Dr. Harp began her presentation by discussing skin changes that can occur in dermatomyositis (DM). These include:

• Scalp rash – A common skin finding in DM that can be difficult to see and may look like flaking of the scalp.
• Heliotrope rash, which has a purple hue and appears on the eyelids; this rash also swelling also occurs with this rash.
• Holster sign, rash along the outer, upper thighs.
• Gottron’s Papules, which are bumps over the joints.
• Midfacial erythema, redness of the skin.
• Periungual erythema, redness around the fingernails.
• Shawl sign, a rash around the upper back, just below the neck.
• Poikiloderma, a discoloration of the skin resulting from the combination of dilated blood vessels, hyperpigmentation, hypopigmentation, and mild skin thinning.
• Photosensitivity, sensitivity to the sun.
• Mechanic’s hands, in which the skin appears flaky and feels “broken down.”
• Ragged cuticles.
• Changes around the nailfolds.
• Calcinosis cutis, calcium growth that appear as very hard nodules under the surface of the skin.

Dr. Harp went on to explain that in DM, inflammation occurs where the dermal and epidermal layers of the skin meet. DM is an inflammatory myopathy (disease of the muscle tissue) with specific and non-specific skin lesions described above. Skin disease often develops before muscle disease; Dr. Harp recommended that all people with DM who have skin lesions should be evaluated for muscle and lung disease, and undergo cancer screenings, even if no other symptoms are present. It is thought that the risk for developing cancer is increased for 3 years after DM diagnosis, and potentially for up to 5 years. Dr. Harp stated that, since ovarian cancer is over-represented in women with DM, she would recommend transvaginal ultrasound or other imaging for her patients with the condition. Some patients may opt for additional screening in consultation with their primary care physician/rheumatologist.

Other types of dermatomyositis include:

• Amyopathic dermatomyositis: there is no development of muscle disease after more than 2 years of diagnosis; this condition rarely progresses to muscle disease after a 2-year period and carries the same risk of lung disease and cancer previously described.
• Provisional amyopathic dermatomyositis: between 6 to 23 months of skin disease without muscle involvement.
• Hypomyopathic dermatomyositis: the patient has no symptoms, but does have positive lab findings that indicate inflammation of muscles.

What can be done?

Dr. Harp presented various skin-focused treatments. She emphasized the importance of topical (external) treatments and protection from the sun.

Topical treatment can include steroids applied to the affected areas. When used correctly, the risk of side effects is low. Depending on the part of the body that is being treated, different strengths of steroids may be used. In addition, different areas of the body require different forms of treatment. Ointments, which are Vaseline-based tend to be stronger than creams.

As an example, Dr. Harp described the treatment of a 56-year-old patient with dermatomyositis, with involvement of the scalp, eyelid, and chest, as well as hand rash, in which each area that was affected was treated with different types and strengths of topical agents. It is important to note that each individual requires different treatment and that this is best discussed with your doctor.

Protect your skin from the sun!

• Dr. Harp emphasized the importance of using broad spectrum (which offers protection from both UVA and UVB rays) sunscreen on exposed parts of the body all year round. For instance, during colder weather, when less skin is exposed, it is still important to protect your hands and face.
• UVA rays are not blocked by glass, so patients are still at risk when driving, as UVA rays can penetrate car windows.
• The American Academy of Dermatology recommends using a sunscreen with a label that states:
  • SPF of 30 or higher. Dr Harp added that she would recommend an SPF of about 50 for people with DM.
  • Broad spectrum (protects skin from both UVA and UVB rays).
  • Water resistant for up to 40 or 80 minutes (after this period of time, sunscreen may not be waterproof or sweat proof).¹

Itching

Dr. Harp noted that itching can be a debilitating effect of DM. Patients experiencing this symptom should speak with their doctor, who may recommend oral and/or topical options for treatment.

Beyond topical treatment

Individuals who do not achieve symptom relief with topical treatment should consult their doctor. He or she may consider prescribing antimalarials, such as Plaquenil (hydroxychloroquine). According to Dr. Harp this class of drugs helps 40-75% of people with DM.

Dr. Harp stated that antimalarials have UV (ultraviolet) protective benefits and are not immunosuppressives. There is a rare risk of a flare of DM symptoms, but the benefit may outweigh the risk.

Owing to a risk of side effects that affect vision, an eye exam is recommended before starting antimalarials and then yearly after 5 years of initiating treatment.

Dr. Harp also described treatment options that may be used when skin disease is more severe. These include:

• Prednisone as the first line of defense if muscle disease is also present.
• Non-steroid options, which may include methotrexate, CellCept (mycophenolate mofetil), and intravenous IVIG (immunoglobulin).
• TNF-alpha blockers, drugs that block TNF-alpha, which is part of the inflammatory cascade that can cause inflammation in skin, muscles, and other parts of the body.
• Rituxan (rituximab), if lung/muscle disease is severe.

Learn more about the HSS Myositis Support Group, a free support and education group, held monthly for people with myositis and their family and friends.

1. How to Select a Sunscreen, American Academy of Dermatology

 

Summary by Suzan Fischbein, LCSW, Social Work Coordinator, Myositis Support Group
Edited by Nancy Novick

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