DERMATOMYOSITIS

Dermatomyositis is one of the autoimmune connective tissue diseases. The name is derived from dermato=skin, myo=muscle, and itis=inflammation. Thus, inflammation of unknown cause leads to a distinctive skin rash and weakness and tenderness of the muscles, particularly of the hip and shoulder girdles.  Dermatomyositis (DM) affects women more than men (about 2 to 1), usually between the ages of 40 and 60 years, but there is also a childhood form of DM.

Heliotrope Sign of Dermatomyositis

Heliotrope Sign of Dermatomyositis

Most patients with DM are photosensitive, and from the point of view of a dermatologist, often note the onset of the rash after a prolonged or exaggerated sun exposure. As I will discuss, although some of the skin features of DM are diagnostic by recognition, they may not always be present, and the muscle weakness may not appear until months later. The picture is further complicated by the possible association or overlap of DM with scleroderma, lupus, and rheumatoid arthritis.

When all the pieces of the puzzle fit together, DM is a dermatologist’s dream because DM has a host of special “signs” attributed to it that aid in differentiating it from lupus, lichen planus, and psoriasis.

  1. This case shows features of lupus and dermatomyositis with dermatitis involving knuckles and skin between knuckles.

    This case shows features of lupus and dermatomyositis with dermatitis involving knuckles and skin between knuckles.

    Heliotrope sign: named after the flower, refers to violet discoloration and subtle swelling of the upper eyelids or the entire peri-orbital skin.

  2. Gottron's papules in a child with Dertmatomyositis

    Gottron’s papules in a child with Dertmatomyositis

    Gottron’s papules: reddish violet bumps or plaques overlying the knuckles and
    possibly the elbows and knees.

  3. Shawl sign: sun-damage of the upper back and chest showing thinning of the skin, decreased and increased pigment, and dilated blood vessels. Together, these skin changes are called poikiloderma.
  4. Poikiloderma of sun-exposed skin in Dermatomyositis with calcinosis cutis

    Poikiloderma of sun-exposed skin in Dermatomyositis with calcinosis cutis

    Holster sign: poikiloderma on the sides of the thighs.

  5. Enlarged and dilated capillaries of surrounding fingernails

    Enlarged and dilated capillaries of surrounding fingernails

    Enlarged, dry cuticles and dilated capillaries around the fingernails.

  6. Redness, scaling, and itching of the scalp may be easily confused with psoriasis.

Laboratory tests performed to clarify the diagnosis may actually confuse the picture. Here’s why: most clinicians will be considering lupus because of the photosensitivity and the presence of “rashes.” The anti-nuclear antibody blood test is positive in 2/3 cases of DM which can mislead. A skin biopsy generally shows an “interface dermatitis” which indicates a connective tissue disease but is not specific for either lupus or DM. Direct immunofluorescence testing of the skin biopsy specimen will be negative in DM or show non-specific results which can also be seen in lupus.  However, even if there is no muscle weakness demonstrated, the muscle enzymes in the blood may be elevated, an indication of inflammation producing muscle damage. Skin manifestations may precede muscle disease in 50% of cases, but myositis can eventually be detected during the following 6 months using tests such as MRI, electromyogram, and muscle biopsy.

Thus, photosensitivity, the presence of some of the listed skin signs (especially #1 and 2), and elevated blood levels of creatine kinase and/or aldolase can clinch the diagnosis of DM.

Treatment of Dermatomyositis

Enlarged dry cuticles and Gottron's papules

Enlarged dry cuticles and Gottron’s papules

There is a partial disconnect between the treatment of the skin and muscle inflammation in DM. The myositis usually responds to high dose systemic prednisone, but rashes are often resistant. Plaquenil or hydroxychloroquine improves about 80% of DM patients with skin signs but does not help myositis. Skin treatment must also include sun avoidance and sunscreen use; topical creams such as corticosteroids, tacrolimus, and pimecrolimus may improve the rashes. Then there are some drugs that can help both skin and muscle manifestations. These are intravenous immunoglobulin (IVIG), methotrexate, mycophenolate mofetil, cyclosporine, and rituximab.  A  paper in the Journal of the American Academy of Dermatology (October 2013) reported on the successful treatment of 13 DM patients with resistant skin disease. All 13 patients improved, and 8 cleared completely with IVIG at a dose of 2 grams per kilogram infused every 4 weeks. In all cases, the dosages of prednisone or other immunosuppressive drugs could be reduced or discontinued thereby lowering the risk of side-effects.

Association with Cancer

It has been established that patients with DM have a higher than expected incidence of internal cancer within the first 3 years of the DM diagnosis. Cancer develops in 15-30% of patients during this time period. The types of cancers reported are quite variable and may include uterine, ovarian, lung, pancreatic, colon, and lymphoma. Screening for internal malignancy is recommended at the diagnosis of DM and  annually for 3 years utilizing body CT scans, mammogram, PAP smear, chest X-ray, colonoscopy, and other age- and gender-appropriate tests.  If the rash improves or clears after the cancer is discovered and treated, a later flare-up of DM requires a search for recurrence or spread of the cancer.

More About Autoimmune diseases:
Importance of the Second Opinion: Editorial with Illustrative Cases
Dermatitis Herpetiformis

 

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32 Responses to DERMATOMYOSITIS

  1. V says:

    I have Amyopathic Dermatomyositis. Thank you for your overview of the disease. Can you expand on what you do in practice to treat someone with resistant skin disease but no muscle involvement? Will insurance carriers approve expensive IVIG only for skin manifestations? Have you had good results with tacrolimus creams alone?

    • DrCamisa says:

      Tacrolimus ointment has been reported to help, but I haven’t prescribed it for DM because of high cost and large areas of skin to cover. For skin manifestations only, I usually prescribe plaquenil, methotrexate, and mycophenolate (CellCept) in that order. I think after topical and oral treatments have been tried and proved ineffective, it may be possible to get IVIG covered by insurance as medically necessary.

  2. Julie says:

    I have resistant refractory cutaneous amyopathic DM. I have tried cellcept, methotrexate, Imuran, IVIG and Rituxan with no improvement. Friday will be my 3rd dose of Remicade last one was on 02/14/14. I am seeing some improvement, but this past week and seeing my Dermatologist yesterday, it seems to be worse again. In my situation what would be your next line of treatment? I will not take oral Tacrolomis as too risky. Currently I’m on Hdroxyqloriqine, I’ve tried Protopic with no results and yesterday was given a prescription for primcroliumos. I would just like another’s Dr. opinion on my situation. Thank you for your time.

    • DrCamisa says:

      It’s rare to have a case of DM that is so resistant to therapy, but I have seen it. It is usually necessary to combine several of the medicines you listed at the same time, for example, I saw one recently that needed to be treated with IVIG, methotrexate, plaquenil, and prednisone to get into remission. Now, each drug is being weaned off one at a time. By the way, oral tacrolimus is a reasonable drug to try. Protopic is actually topical tacrolimus. Pimecrolimus is basically the same chemical.

      • Julie says:

        I’m sorry, I forgot to add I’m on 5mg of prednisone, however that did nothing to help. What would happen if an amyopathic DM patient such as myself that nothing is working for my skin and has extreme photosensitivety if I just stop all medication therapy. I guess what I’m trying to say is “What is my outlook” for not treating amyopathic DM. Thank you again for your time

        • DrCamisa says:

          Speaking generally of all cases of amyopathic DM, if all treatment is stopped, any improvement gained would likely be lost. There is always the chance that myopathy or inflammation of the muscles might develop, but this becomes less likely after the first few years of the disease. Another possibility is that the disease would eventually “burn out” and go into remission.

          • Julie says:

            Thank you Dr. for your reply. That’s exactly what my Dermatologist said so you as well are very educated and knowledge in this rare autoimmune disease. I have my 3rd Remicade Infusion this morning and to meet with my Oncologist/Heamotologist to see if it’s working. I will update you. Again, thank you for your time to reply to me.

  3. Gerry says:

    Dr Camisa,
    This thread is very informational, I have an additional question if possible,

    I have DM with my lungs being affected and shortness of breath and skin rash on eyes,
    hands and elbows its 18 months now,

    I Did Ivig treatment with Solumedrol IV every 4 weeks for a year and did not feel this fatique then.

    im on Plaquenil cellcept and prednisone 5mg dailycurrently.
    Protopic topical cream did not help at all by the way.

    question:
    (I am continually tired and lack energy most days, lately,
    is it normal?)

    regards

    Gerry

    • DrCamisa says:

      All that treatment can contribute to the fatigue while it’s helping the DM. I would suggest supplements to help with your energy, especially resveratrol, CoQ10, B complex, and magnesium.

  4. Yvonne says:

    I have had Amyopathic Dermatomyositis since late 2011. Predisone, Methotrexate and Plaquenil have controlled it. I have been off Predisone for 3 mos. This is the longest time I have been off of it. I do have flares with itching and fatigue but no rash. Is this normal or is there a normal with this disease?

    • DrCamisa says:

      It’s great that you are fairly well maintained off prednisone. You may have subclinical disease where there is no rash visible, but you have itching. Watch your sun exposure which can also cause itching. Fatigue can also be a sign of your illness, but remember that it is also a very common side-effect of methotrexate itself.

  5. I’ve been diagnosed with Amyopathic Dermatomyositis and have had the CK and Aldolase, along with other labs, but no one I have seen has ordered the Myositis-Specific Panel. Antibodies included in the Myositis-Specific Panel include: Mi-2, PL-12, PL-7, EJ, OJ, Ku, U2 snRNP, SRP, PM/Scl, Jo-1, SSA-52 kd, P140, P155/140, U1 snRNP, U3 RNP Fibrillarin. Do you know why physicians don’t order this panel since it could be beneficial to those presenting with ADM when diagnostic testing for muscle involvement is negative?

    • DrCamisa says:

      Most of these tests are considered investigational and have a very low yield for “amyopathic dermatomyostis” which literally means “no muscle pathology.”

  6. E. S. says:

    Thank you for the helpful article. I’m in the diagnosis process, waiting to see a dermatologist, and would like your opinion on appropriate skin biopsy sites. Do you generally biopsy over the location of Gottron papules, or would nearby erythematous skin on the phalanges do as well? What about newly abnormal (discolored and “pebbly”) skin over the dorsum of the forefoot? If you can point me toward an article on biopsy site selection, that would be great too. A lot of the clinical literature that I’ve seen so far just analyzes the histopathology without even indicating the biopsy site. Thank you!

    • DrCamisa says:

      That’s a very good question. I haven’t really seen anything in textbooks about that, but I have taken biopsies from both of the hand places you mentioned, and they were both positive. A biopsy isn’t always absolutely necessary if most of the clinical signs I described in the article are present. An exception would be if there’s just facial, chest and upper back redness from sun sensitivity where it’s difficult to differentiate from lupus. In such a case, a routine biopsy plus one for direct immunofluorescence would be very helpful.

  7. Anne says:

    My mother has just been diagnosed with DM, with muscle involvement. Her muscle enzyme levels have been slightly elevated for about ten years, and she has noticed a loss of muscle mass over the past several years. She has the classic heliotrope rash on her eyes, esophagus problems (failed a swallow test), and as of this year dozens of skin cancers have started popping up all over her body. I am concerned, as it seems to have taken so much longer than usual to get a diagnosis and therefore begin treatment, and also because she has so many symptoms. In a case like this, do you have any idea what the chances are that she will go into remission after starting therapy? Just trying to get an idea of what we are facing here. Thank you.

    • DrCamisa says:

      I don’t think the chances of a good response to treatment would be affected by a delay in diagnosis. I also don’t think the development of skin cancers is related to the diagnosis of dermatomyositis.

  8. Sue Corbett says:

    I have what, to my eye, appear to be Gottron’s papules over the knuckles of my hands and fingers and a rash on the palms of my hands and fingers that looks like mechanic’s hands. I’d say I’ve had it for at least 3 years and it has progressively worsened. Recently, a dermatologist took one look and spoke of DM. A biopsy came back as possibly Lichen Planus Complex although direct immunofluorescence was consistent with DM. CK and myositis antibodies were normal. The dermatologist ‘favoured’ a diagnosis of ASS/DM with mechanic’s hands but said it was dependent on the blood tests to come. I gathered from a phone call with the rheumy that the negative bloods meant I don’t have it. I am not convinced. What constitutes a diagnosis of ADM?

  9. Sue Corbett says:

    Sorry. Forgot to add thank you! I have also just been diagnosed with Sarcoidosis. I have been having trouble with breathlessness and swallowing (at times) and the Thoracic doctor thought those problems may stem from enlarged lymph glands in my chest. The Dermatologist considered these symptoms when he made his diagnosis. I understand there’s no relation between the two diseases, except for similar lung problems but it has been very strange to get diagnosed with two rare diseases within 24 hours and then confirmed a week apart. Only to have one – the DM – retracted several weeks later. I need to know!

    • DrCamisa says:

      Sarcoidosis of the skin has been called the “great imitator” because it may resemble so many other skin diseases.

  10. Thanks for a really clear explanation about Dermatomyositis. I’ve heard people get benefit from using cannabis oil to help with the soreness and itching. Is this something worth to try?

  11. Nikki kemp says:

    Hi there, I’ve just had a skin biopsy from a heliotrope erruption on my face and it showed bit lupus and DM why would this be please and is this saying that I have both..?

    • DrCamisa says:

      Both DM and lupus show an “interface dermatitis.” On routine staining of the biopsy, it is very difficult to tell the difference between the two diseases. Direct immunofluorescence testing of the skin biopsy may help to differentiate them.

  12. Max says:

    Hello.
    I’ve been dealing with a rash on both my hands for a little over a month now. It feels like sun burn and kind of looks like it too. Finally made it to the dermotologist and they think I have DM. Besides the rash I feel healthy. I’m a 28 year old athletic male. I go to the doctor to get a rash checked out and I leave thinking I have an autoimmune disease. Is it really that easy to diagnose with just a visual inspection of the rash? I’m awaiting a skin biopsy
    Thank you for your time.

    • DrCamisa says:

      “Easy to diagnose” would not be a phrase I use for this disease. The signs I described and illustrated in my article are very suggestive in the right clinical circumstances. However, skin biopsies, certain blood tests, and possibly electromyogram and muscle biopsy may be necessary to confirm the diagnosis.

  13. Kim says:

    Hi. I have been diagnosed with ADM for over two years and have very classic symptoms with Gottron’s on my hands and small ulcerations on my fingertips. I understand these ulcerations may be indicative of a predisposition for ILD if antibodies are present. I do not have the antibodies. Should I still be concerned ? Is the vasculitis seen on my fingertips also present in other vessels in the body? Can it cause ulcerations or infarcts elsewhere like the bowel or brain? Thank you for your time and consideration.

  14. I was diagnosed 8 years ago with DM. The muscle weakness and pain went away within 2 weeks of starting Prednisone and Methotrexate and have never returned. I was only mildly symptomatic over the next 6 years, rash and itching mostly. My biggest complaint was hair thinning. 1 1/2 years ago this skin irritation and itching flared up. My rheumatologist prescribed CellCept. 3 grams. I have taken that for over a year with no improvement. Most recently I have been seen by dermatology at the Mayo Clinic. Now they want to try Tacrolimus. I work and travel all over the country for work. I also like to have a glass or 2 of wine or beer at the end of a workday. I am actually afraid to take this drug. I would like a professional second opinion.

    • Dr. Camisa says:

      I assume you mean oral tacrolimus? You have followed a good logical progression of treatment up to now, and you have been to an excellent institution for consultation. I cannot give you a professional opinion regarding your specific case because I have not treated DM with tacrolimus. However, I have used the drug for lichen planus, another autoimmune disease.

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