Dermatomyositis Treatment & Management

Updated: Sep 26, 2018
  • Author: Alisa N Femia, MD; Chief Editor: Herbert S Diamond, MD  more...
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Treatment

Approach Considerations

Therapy for dermatomyositis involves both general measures and specific measures to control the muscle disease and the skin disease. In addition, some patients with dermatomyositis need treatment for other systemic manifestations or complications.

The muscle component is treated by administering corticosteroids, typically with an immunosuppressive agent. The skin disease is treated by avoiding sun exposure and by using sunscreens and photoprotective clothing, as well as with topical corticosteroids, antimalarial agents, [64] and immunomodulatory medications such as methotrexate, mycophenolate mofetil, or intravenous immunoglobulin.

Surgical care is usually unnecessary in the management of dermatomyositis. Some patients may benefit from surgical removal of focal areas of calcinosis, particularly those that are painful. Inpatient care is needed for patients with fulminant dermatomyositis with muscle and/or internal organ involvement.

Children and adolescents are much more prone to the development of calcinosis. Aggressive and early treatment may prevent this complication.

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General Measures

Several general measures are helpful in the care of patients with dermatomyositis. Bed rest is often valuable for those with severe inflammation of the muscles.

In patients with muscle weakness, especially children, a program of physical therapy is useful to help prevent the contractures that can complicate the disease when patients do not fully move their joints. Rehabilitative exercise is also recommended for both adult and pediatric patients in order to maintain muscle strength, even during the course of active muscle disease.

For patients with dysphagia and/or gastroesophageal reflux, elevation of the head of their bed and avoidance of eating prior to bedtime are helpful. These simple maneuvers may prevent aspiration pneumonitis. Occasionally, nasogastric tube feeding is needed to increase caloric input.

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Treatment of Muscle Disease

The mainstay of therapy for the muscle disease is systemically administered corticosteroids. [65, 66, 67] Traditionally, prednisone (0.5-2 mg/kg/d) up to a dose of 60 mg/d is given as initial therapy. The drug should be slowly tapered to avoid relapse of the disease. Because most patients develop steroid-related toxic effects, most authorities administer a steroid-sparing immunosuppressive or cytotoxic agent early in the course. [68] Drugs reported to be steroid-sparing in some patients or in small open-label studies have included the following [69, 70, 71, 72] :

  • Methotrexate
  • Azathioprine
  • Cyclophosphamide
  • Cyclosporine
  • Mycophenolate mofetil
  • Leflunomide
  • Chlorambucil
  • Tacrolimus

Generally, methotrexate, mycophenolate mofetil, or azathioprine are used first line as glucocorticoid-sparing agents for muscle involvement. Response rates to methotrexate have been reported to be approximately 70-80%. [73] In addition, one small, randomized trial supported the long-term benefits of azathioprine as compared with prednisone monotherapy. [74] Results with cyclophosphamide in severe cases have been disappointing.

For refractory cases, the use of monthly high-dose intravenous immune globulin (IVIG) for 6 months has proved beneficial in the short term. [75, 76] In addition to its positive effects on refractory muscle and skin disease, IVIG has been reported to be beneficial for other systemic manifestations, including severe esophageal dysfunction. [77]

Rituximab, a chimeric antibody directed against CD20+ B cells, may be effective, but results have been mixed. [18, 78] In a multicenter, randomized, double-blind placebo-controlled trial of 44 weeks of rituximab therapy in patients with dermatomyositis and polymyositis, most patients experienced improvement in muscle disease activity; however, no significant differences were noted between groups based on muscle parameters. The study had a delayed-start design, with rituximab started immediately in one arm and after 8 weeks in the second arm, which is speculated to have influenced the results. [78]

An analysis of 195 patients with polymyositis and dermatomyositis looked to determine predictors of response to rituximab, and found that antisynthetase and anti-Mi2 autoantibodies, as well as lower disease damage and juvenile-onset disease, were predictors of clinical improvement with rituximab. [79]

The calcineurin inhibitor tacrolimus appears to be effective, safe, and well tolerated in patients with dermatomyositis that is refractory to other treatments. In addition to improvement in muscle strength and physical function, amelioration of skin lesions and interstitial lung disease have been reported. However, randomized, controlled trials have yet to be conducted. [80]

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Treatment of Skin Disease

Therapy of cutaneous disease of dermatomyositis is often difficult. Some patients with dermatomyositis present primarily with skin disease (ie, amyopathic dermatomyositis [ADM]), whereas others present with a muscle component that is controlled but with significant ongoing skin disease.

First-line therapy is to recognize that the patient is photosensitive and to prescribe sun avoidance and sun protection measures, including broad-spectrum sunscreens and photoprotective clothing. The cutaneous component of dermatomyositis is exacerbated by sunlight and other sources of ultraviolet light; in addition, the muscle component may be exacerbated.

Hydroxychloroquine and chloroquine have been beneficial in small, open-label case studies; [81, 82] however, roughly 25-30% of patients with dermatomyositis who are treated with hydroxychloroquine develop a drug eruption, and patients should be counseled regarding this potential side effect. [81] Some patients who develop a drug eruption to hydroxychoroquine may go on to tolerate chloroquine. [81]  

In a study of 111 patients with dermatomyositis who were treated with hydroxychloroquine, Wolstencroft et al found a link between risk of skin eruptions and autoantibody subsets. Skin eruptions occurred in 7 of 14 patients with antibodies against small ubiquitinlike modifier 1 activating enzyme (SAE-1/2) but in only 16 of 97 patients without anti-SAE-1/2 autoantibodies (50.0% versus 16.5%, respectively). None of 15 patients with autoantibodies against melanoma differentiation-associated gene 5 (MDA-5) had a skin eruption, versus 23 of 96 (24.0%) of those without anti-MDA-5 autoantibodies. [83]

Methotrexate is often considered first-line systemic therapy if antimalarials fail or are contraindicated. [84] Mycophenolate mofetil has been reported to be useful as well. [69, 85, 86, 87, 88]

Azathioprine has been reported to be effective for muscle involvement, but there is a paucity of literature regarding cutaneous response. Azathioprine appears to be less effective for cutaneous disease. Sirolimus, tactrolimus, and dapsone inhibitors are among other immunomodulatory medications that may be of value in some patients. [89, 90, 91, 80] In addition, small case series or individual reports of successful management with leflunomide have also appeared in the literature. [72]

Intravenous immune globulin (IVIG) has benefited muscle involvement and cleared the skin lesions in the patients in whom it was used. A retrospective evaluation of 42 patients with dermatomyositis compared 24 patients treated with IVIG as an add-on to conventional immunosuppressive therapies to those treated with conventional immunosuppression alone. This study found that muscular and cutaneous involvement were significantly improved at 6 months in the IVIG-treated group, and modified Cutaneous Dermatomyositis Area and Severity Index (CDASI) scores were significantly improved over pretreatment scores during 4 years of follow-up, despite no significant difference in cutaneous remission rates and a high cutaneous relapse rate. [92]

Subcutaneous IgG has also been effective in dermatomyositis. [93] Rituximab has been used for skin disease, but the results are mixed. [19, 78] In a trial that included 72 adult patients DM, Aggarwal et al reported improvement in refractory skin rashs after the addition of rituximab to standard therapy. The most significant improvement occurred in erythroderma, erythematous rashes without secondary changes of ulceration or necrosis, heliotrope, Gottron sign, and papules. A trend for faster cutaneous response (20% relative improvement from baseline) was noted when rituximab was given early (week 0/1) rather than late (week 8/9). [20]

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Management of Calcinosis

Calcinosis, a complication of dermatomyositis, is particularly likely to affect children and adolescents. Some experts believe that aggressive early treatment of the myositis may aid in preventing calcinosis. Once established, the process of calcinosis is debilitating in many patients. Although spontaneous remission is possible, it often takes many years to occur.

The use of the calcium channel blocker diltiazem (240 mg bid) is reportedly associated with gradual resolution of calcinosis in a small number of cases. [94] In addition, the use of an oral bisphosphonate might be helpful. [95] Intravenous (IV) pamidronate has been demonstrated in several cases to result in resolution of the calcinosis. [96] Colchicine, alendronate, and warfarin appear to be potentially beneficial for the resolution of calcinosis, although the data are not conclusive.

Some patients with localized areas of calcinosis may wish to have the calcinotic nodules surgically removed, particularly if they are tender. A retrospective study from the Mayo clinic of 78 patients with dystrophic calcinosis in the setting of autoimmune connective-tissue disease (of which dermatomyositis and systemic sclerosis were the most common underlying diseases) found that surgical excision and diltiazem produced the best results in diminishing calcinosis. [97]

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Diet and Activity

A well-balanced diet is useful. Patients with severe muscle inflammation may need extra protein to balance their loss. Patients with dysphagia should avoid eating before bedtime; they may require a special diet, depending on the severity of the esophageal dysfunction.

Sun avoidance and sun protection measures are recommended in patients with skin lesions. Patients with dermatomyositis should maintain activity as much as possible. Although vigorous physical training should be avoided when the myositis is active, a rehabilitative exercise regimen is typically still recommended during the course of active muscle disease. Exercises to maintain the patient's range of motion are also advised.

Resistance training and aerobic exercise may also be beneficial for muscle involvement, especially if instituted early. In a randomized controlled trial, 12 weeks of endurance exercise yielded improvement in muscle performance, maximal oxygen consumption (VO2 max), and activities of daily living as compared with a non-exercising control group. In a 1-year open-label extension follow-up, improvement in muscle performance was sustained, but other assessments returned to baseline, emphasizing the need for a continued exercise program. [98]

Another randomized controlled trial of 19 patients compared patients with recent-onset polymyositis/dermatomyositis assigned to 12 weeks of resistive home exercise with telephone support, along with encouragement for another 12 weeks of home or gym exercise, with a control group assigned to 24 weeks of range-of-motion exercises. Both groups experienced improvement in muscle performance and aerobic capacity, but there were no significant differences between groups. In an open-label 2-year follow-up, the exercise group maintained significant improvement in muscle performance and aerobic capacity compared to baseline, suggesting that sustained exercise may be of some benefit. [99]

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Consultations

Consultations with the following specialists may be indicated:

  • Rheumatologist
  • Dermatologist
  • Neurologist
  • Medical or surgical oncologist (for patients with cancer)
  • Internal medicine specialist or pediatrician (depending on patient age)
  • Pulmonologist
  • Cardiologist
  • Gastroenterologist

Patients with dermatomyositis may be served better by a physician or a team of physicians who have experience in managing this relatively rare disorder. Transfer to a tertiary center is often warranted for initial care and even for follow-up care.

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Long-Term Monitoring

Disease activity must be closely monitored. Repeat measurements of muscle enzymes and clinical assessment of patients' strength may facilitate assessment of the activity of the myositis. Machines that can aid in the quantification of strength are available but are not used widely. The American College of Rheumatology and the European League Against Rheumatism have developed criteria for clinical response to treatment in patients with dermatomyositis; however, these are principally intended for use in clinical trials. [100]

The skin component of dermatomyositis is assessed by means physical examination in conjunction with history taking. The Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI), the Dermatomyositis Skin Severity Index (DSSI), and the Cutaneous Assessment Tool (CAT) skin indices have been developed as outcome instruments. The CDASI has been found to be valid and responsive for characterizing cutaneous dermatomyositis severity and detecting improvement in disease activity. [101] Further testing to compare the responsiveness of all three measures is necessary. [102]

Annual physical examinations are useful to monitor for potential toxicity due to therapy or for the presence of a malignancy.

Malignancy evaluations, including imaging studies as noted above, should be conducted annually for at least the first 3 years after diagnosis. A report by Hill et al suggested that the risk of malignancy never returns to baseline, even after 3 years; thus, continued vigilance is warranted. [7]  However, most data suggests that the majority of dermatomyositis-associated malignancies occur within the first 3-5 years after diagnosis.

Selection of testing should be based on the patient's age, sex, race, and other symptoms or findings. Typically, a workup more extensive than age-appropriate screening is recommended. The principal malignancies associated with dermatomyositis are ovarian cancer and breast cancer in females and lung cancer in males. [103] After 3-5 years, patients should be monitored in the same manner as any other person of their same age, race, and sex.

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Further Reading

The reader is referred to articles by Callen and Wortmann (2006), Iorizzo and Joizzo (2008), and Krathen et al (2008) for further reading.

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