Dermatomyositis is a skin disorder characterized by a number of clinical signs and symptoms. Dermatomyositis is an uncommon disease marked by muscle weakness and a distinctive skin rash. Because of similarities in signs, symptoms and treatment, dermatomyositis is often discussed in conjunction with polymyositis. Both conditions fall into the category of inflammatory muscle diseases — "myo" means "muscles" in Greek; "itis" means "inflamed." "Derma," means "skin." Although dermatomyositis may occur at any age, it mostly affects adults in their late 40s to early 60s or children between 5 and 15 years of age. Women have dermatomyositis more often than men do. Those with this disease have a higher risk of cancer with an increased risk of mortality due to visceral involvement. Cutaneous involvement has no vital impact on mortality but considerably affects the quality of life of the patients and can resist to classical therapies.

Many classification schemes are available, based on internal organ involvement, presence of circulating autoantibodies and additional symptoms characteristic for other connective tissue diseases. The prognosis of the individual patient depends on the involvement of internal organs and the characterization of circulating autoantibodies.

Juvenile dermatomyositis
This is a rare disease of childhood with significant morbidity. Although the mortality and morbidity has improved over recent decades, it is still a chronic disease for a significant proportion of children with juvenile dermatomyositis. There is a lack of controlled trials in both adult and juvenile dermatomyositis and hence alternative treatments are difficult to find. The treatment of juvenile dermatomyositis often involves methotrexate and aggressively tapered steroids.

While corticosteroids and disease-modifying anti-rheumatic drugs improve outcomes, many children experience refractory disease.

Dermatomyositis symptom
The most common signs and symptoms of dermatomyositis include: A violet-colored or dusky red rash, most commonly on the face, eyelids, and areas around your nails, knuckles, elbows, knees, chest and back; Progressive muscle weakness, particularly in the muscles closest to the trunk, such as those in hips, thighs, shoulders, upper arms and neck. This weakness is symmetrical, affecting both the left and right sides of the body; difficulty swallowing (dysphagia); muscle pain or tenderness.

Polymyositis and dermatomyositis information
Polymyositis and dermatomyositis are inflammatory myopathies that differ in their clinical features, response to treatment, and outcome. Although their clinical pictures differ, they both present with symmetrical, proximal muscle weakness. Medical treatment relies upon empirical use of corticosteroids and immunosuppressive agents.

Interstitial lung disease is a common complication of polymyositis and dermatomyositis, and accounts for a significant proportion of their morbidity and mortality because of the resistance to therapeutic agents including corticosteroids. They may be associated with other autoimmune diseases such as myasthenia gravis, Hashimoto's thyroiditis, systemic sclerosis and Waldenstrom's Macroglobulinaemia. Damage to capillaries would seem to be an underlying pathology in dermatomyositis.

Semin Arthritis Rheum. 2018. The effect of cigarette smoking on the clinical and serological phenotypes of polymyositis and dermatomyositis. Cigarette smoking is associated with immune-mediated disorders. We explored the contribution of smoking to polymyositis (PM) and dermatomyositis (DM) phenotypes and attempted to determine whether cigarette smoking effects differ by race and genotype. Tobacco smoking was associated with clinical and autoantibody phenotypes in Caucasians.

Mod Rheumatol. 2018. Current diagnosis and treatment of polymyositis and dermatomyositis. Idiopathic inflammatory myopathies (IIMs) are disorders that affect the skeletal muscles. Polymyositis, dermatomyositis, and inclusion body myositis are major IIM subsets. Immune-mediated necrotizing myopathy became recognized as a potentially new IIM subset. Glucocorticoids are used empirically as the first-line treatment despite their various adverse effects. Concomitant treatment with steroid-sparing immunosuppressive agents, including methotrexate, azathioprine, calcineurin inhibitors, mycophenolate mofetil, and cyclophosphamide, reduces successfully initial glucocorticoid doses for the remission induction, the relapse risk during glucocorticoid tapering, and adverse effects of glucocorticoids. Treatment with biologics, including rituximab and abatacept, seems promising in some IIM patients.

Q. I am 54 years old. I was diagnosed with Polymyositis two years ago. I went to a neurologist and was prescribed asteroid (corticosteroid). I have taken it for 1.5 years. My RA test was positive but NTCCP (its confirmatory test) was negative. Also, I am not suffering from dermatomyositis. You mention about natural treatment of Autoimmune disease through diet for rheumatoid arthritis. Can I have to follow the same diet in my case (i e for polymyositis)? I have tried every kind of medicine, be it Ayurveda, homeopathy or allopathy. All was vain. My fever never went down using them except for 2-3 days. It always remains 100-101°F. I feel so pathetic at times. I have lost all hopes.
   A. I am not an expert on polymyositis, but it is worth trying out an anti-inflammatory diet as mentioned in my autoimmune disease article.

Dermatomyositis treatment
There are patients with rapidly developing subsets of dermatomyositis and those with slowly progressive disease. Therefore treatment has to be adjusted for the disease severity. Sometimes high dosages of corticosteroids in combination with immunosuppressive agents or immunoglobulins are required.
   Tacrolimus is an immunosuppressive agent and topical tacrolimus is used for the treatment of atopic dermatitis and has been occasionally used to treat skin involvement of some systemic inflammatory diseases. Topical tacrolimus seems to be a therapeutic alternative for resistant skin lesions of dermatomyositis.

Mod Rheumatol. 2015. Long-term follow-up of 124 patients with polymyositis and dermatomyositis: statistical analysis of prognostic factors. The aims of this study were to clarify the long-term outcome of patients with polymyositis and dermatomyositis (PM/DM) and to elucidate prognostic factors using statistical analysis. We enrolled patients with PM/DM who visited our department from 1990 to 2014. Diagnoses of PM/DM and clinically amyopathic DM were based on the definitions of Bohan and Peter, and Sontheimer, respectively. We also obtained clinical data, such as age of onset, sex, medications, and presence of interstitial lung disease and malignancies, and laboratory tests, including the values of creatine kinase, KL-6, and ferritin. The follow-up was conducted until June 2014.RESULTS:A total of 124 patients (PM: 46, DM: 78) were enrolled. The mean age of onset was 53 years, and females were predominant (64%). Overall survival rate was 93%, 86%, and 78% for 1, 5, and 10 years, respectively. The survival rates were significantly lower in patients with higher age of onset, with malignancies, and with hyperferritinemia in univariate analysis; however, multivariate analysis identified age of onset and serum ferritin as the most significant prognostic factors.

Cause of dermatomyositis
Scientists are still trying to find the cause of this condition. Dermatomyositis belongs to a group of conditions called inflammatory myopathies. Viral infections and underlying malignancies are possible mechanisms to trigger this autoimmune disease. Prescription medications could be another cause.

Tumor necrosis factor inhibitor-associated dermatomyositis; Archives of Dermatology 2010
Dermatomyositis is an autoimmune disease of unknown etiology characterized by inflammation of the skin and muscles. Several medications have been implicated in the development of dermatomyositis; however, the disease has rarely been linked to the use of tumor necrosis factor (TNF) inhibitors. We report 4 cases of dermatomyositis that developed or were exacerbated by exposure to the TNF inhibitors etanercept and adalimumab. Observation Four patients with symptoms of inflammatory arthritis were treated with TNF inhibitors for a duration ranging from 2 months to 2 years. All 4 patients developed symptoms consistent with dermatomyositis, including inflammatory rash and muscle weakness. Their symptoms persisted after discontinuation of the treatment with the TNF inhibitors but responded to treatment with corticosteroids and immunosuppressive medications. Tumor necrosis factor inhibitors have been associated with the onset of a number of autoimmune disorders, most commonly vasculitis and a lupuslike syndrome. Rarely have they been associated with dermatomyositis. The 4 cases reported herein indicate that TNF inhibitor use can be associated with either induction or exacerbation of dermatomyositis.

Pregnancy and dermatomyositis
Polymyositis and dermatomyositis can occur in pregnancy. The role of pregnancy in the disease is unknown. The outcome of the pregnancy seems to reflect the severity of the disease. The more active the myositis during the pregnancy, the greater the chance of fetal loss.

Over the counter remedy
Q. Do you think any supplements can improve or make dermatomyositis worse? I take 5-HTP and also lipoic acid.
     A. I am not aware of any research with supplements for this condition.

Remission and relapse
Email - I was diagnosed as a child at age 10 and was treated until age 15 when the disease went into remission. I am now in my late 30's and I am starting to have some complications with muscle weakness, chest muscle pain and difficulty swallowing. I was wondering if it is common for dermatomyositis to come out of a remission after so long.
   A. I do not know.