Dermatomyositis ( DM ) is a long-term inflammatory disorder that affects muscles. The symptoms are generally a skin rash and worsening muscle weakness over time. This can happen suddenly or develop for months. Other symptoms may include weight loss, fever, pneumonia, or light sensitivity. Complications may include calcium deposits in the muscles or skin.
The cause is unknown. Theories include that it is an autoimmune disease or a result of a viral infection. This is a type of inflammatory myopathy. Diagnosis is usually based on several combinations of symptoms, blood tests, electromyography, and muscle biopsy.
Although there is no cure for the condition, treatment generally improves symptoms. Treatment may include medications, physical therapy, exercise, therapeutics, orthotics, and assistive devices, and rest. The drugs in the family of corticosteroids are usually used with other agents such as methotrexate or azathioprine are recommended if steroids do not function properly. Intravenous immunoglobulins can also increase yield. Most people improve with treatment and in some cases heal completely.
About 1 per 100,000 people per year are newly affected. This condition usually occurs in those in their 40s and 50s with women who are more often affected than men. People of all ages, however, may be affected. This condition was first described in the 1800s.
Video Dermatomyositis
Signs and symptoms
The main symptoms include several types of skin rash along with muscle weakness in both upper arms or thighs.
Skin
One form of a take rash is called "heliotrope" (purplish) or purple, but it may also be red. This can occur around the eyes along with swelling, but also occurs in the upper chest or back of what is called a "scarf" (around the neck) or "V-mark" above the breast and may also occur on the face, upper arm, thigh , or hands. Another form of rash is called red, sometimes scaly, red-exposed papules in one of the joints (metacarpophalangeal or interphalangeal joints). All of these rashes are exacerbated by sun exposure, and are often very itchy, painful, and possibly bleeding.
If a person shows only a typical skin finding of DM, with no abnormal muscle weakness or enzyme, then he or she may have amyopathic dermatomyositis (ADM, formerly known as "dermatomyositis sine myositis".
Muscle
People with DM experience further aggravate muscle weakness in proximal muscles (eg, shoulders and thighs). Tasks that use these muscles: standing from sitting, lifting, and climbing stairs, may prove challenging for DM patients.
More
About 30% of people have joints that are swollen and painful, but these are generally mild.
In some people, this condition affects the lungs, and they may experience coughing or difficulty breathing. If the condition affects the heart, there may be arrhythmias. If it affects the blood vessels in the stomach or intestine, which is more common in children's DM, that person may vomit blood, have a black bowel movement, and may develop a hole somewhere in the gastrointestinal tract.
Maps Dermatomyositis
Cause
The cause is unknown, but may be caused by an early viral infection or cancer, one of which may increase the autoimmune response.
Between 7 and 30% of dermatomyositis arise from cancer, possibly as an autoimmune response. The most common associated cancers are ovarian cancer, breast cancer, and lung cancer. 18 to 25% of people with amyopathic DM also have cancer. Malignancy in relation to dermatomyositis is more common after age 60.
Some cases are inherited, and HLA HLA-DR3, HLA-DR52, and HLA-DR6 subtypes appear to create a disposition for dermatomyositis.
Diagnosis
The diagnosis of dermatomyositis is based on five criteria that are also used to diagnose differently with respect to polymyositis:
- Muscle weakness in both thighs or both upper arms
- Using blood tests, finding higher levels of enzymes found in skeletal muscle, including creatinine kinase, aldolase, and glutamate oxoetherate, pyruvate transaminase and lactate dehydrogenase
- Using electrical signal testing in the muscles, find the following three things: erratic, high frequency recurring signal; short, low energy signals between skeletal muscles and motor neurons that have multiple phases; and sharp activity when the needle is inserted into the muscle
- Examine the muscle biopsy under a microscope and find white blood cells mononuclear between muscle cells, and find the degeneration and regeneration of abnormal muscle cells, dying muscle cells, and muscle cells consumed by other cells (phagocytosis)
- Typical rash on dermatomyositis, which includes a heliotrope rash, Gottron sign, and Gottron papula
The fifth criterion is what distinguishes dermatomyositis from polymyositis; a diagnosis is considered to be definitive for dermatomyositis if three items 1 to 4 are present next to 5, possibly with two in addition to 5, and possibly if only one is present next to 5.
Dermatomyositis is associated with autoantibodies, especially antinuclear antibodies (ANA). Approximately 80% of people with DM test are positive for ANA and about 30% of people have myositis-specific autoantibodies that include antibodies to aminoacyl-tRNA synthetase (anti-synthetase antibodies), including antibodies to histidine-tRNA ligase (also called Jo-1); antibodies to signal recognition particles (SRP); and anti-Mi-2 antibodies.
Magnetic resonance imaging may be useful to guide muscle biopsy and to investigate internal organ involvement; X-rays can be used to investigate joint involvement and calcification.
A case of dermatomyositis may be classified as amygopathic dermatomyositis if only skin is affected and there is no muscle weakness for more than 6 months according to a 2016 review, or two years according to another.
Classification
Dermatomyositis is a form of systemic connective tissue disorder, a class of diseases that often involves autoimmune dysfunction.
It has also been classified as an idiopathic inflammatory myopathy along with polymyositis, autoimmune necrosis myositis, cancer-related myositis, and sporadic inclusion body myositis.
There is this form of disorder that affects children, known as juvenile dermatomyositis (JDM).
Treatment
There is no cure for dermatomyositis, but the symptoms can be treated. Options include medicine, physical therapy, exercise, thermal therapy (including microwave and ultrasound), orthotics and tools, and rest. The standard treatment for dermatomyositis is a corticosteroid drug, administered in pill or intravenous form. Immunosuppressant drugs, such as azathioprine and methotrexate, can reduce inflammation in people who do not respond well to prednisone. Periodic treatment using intravenous immunoglobulin may also improve recovery. Other immunosuppressive agents used to treat the inflammation associated with dermatomyositis include cyclosporin A, cyclophosphamide, and tacrolimus. Physical therapy is usually recommended to prevent muscle atrophy and to regain muscle strength and range of motion. Many individuals with dermatomyositis may require topical ointment, such as topical corticosteroids, for their skin disorders. They should wear high-protective sunscreen and protective clothing. Surgery may be needed to remove calcium deposits that cause nerve pain and recurrent infections.
Antimalarial drugs, especially hydroxychloroquine and chloroquine, are used to treat rashes, because they are in the same condition.
Rituximab is used when people do not respond to other treatments.
In 2016, treatment for amyopathic dermatomyositis in adults did not have a strong evidence base; published treatments include antimalarial drugs, steroids, taken orally or applied to the skin, calcineurin inhibitors applied to the skin, dapsone, intravenous immunoglobulin (IVIG), methotrexate, azathioprine, and mycophenolate mofetil. Nothing seems very effective but among them, IVIG has the best results.
Prognosis
Before the advent of modern treatments such as prednisone, intravenous immunoglobulin, plasmapheresis, chemotherapy, and other drugs, the prognosis is poor.
Dermatomyositis skin manifestations may or may not improve with therapy in parallel with an increase in myositis. In some people, the weakness and turmoil will come together. On the other hand, the two are unrelated, with one or the other more challenging to be controlled. Often, skin diseases continue after sufficient control of muscle diseases.
The risk of death due to this condition is much higher if the heart or lungs are affected.
Epidemiology
The peak incidence of DM at the age of 40-50, but this disease can affect people of all ages. DM prevalence ranges from 1 to 22 per 100,000 people.
History
The diagnostic criteria were proposed in 1975 and widely adopted. Amyopathic DM, also called DM sine myositis, was named in 2002.
Society and culture
- The opera singer Maria Callas (1923-1977) suffered from dermatomyositis from 1975 until his death.
- Actor Laurence Olivier (1907-1989) suffered from dermatomyositis from 1974 until his death.
- American football ran back Ricky Bell (1955-1984), runner-up to the Heisman Trophy in 1976, and number one choice in the NFL draft in 1977, died at the age of 29 from heart failure caused by the disease.
- Rob Buckman (1948-2011) a doctor, comedian, author, and president of the Canadian Humanist Association.
Research
By 2016, research is ongoing to be the cause of DM, as well as biomarkers; ongoing clinical trials for the following drug use in DM: ajulemic acid (Phase II), adrenocorticotropic hormone gel (Stage IV, open label), IMO-8400, Toll-like receptor antagonists 7,8 and 9 (Ph II), abatacept Stage IV, open label), and sodium thiosulfate (Phase II).
References
This article incorporates public domain material from the United States Department of Health and Public Services document, "NINDS Dermatomyositis Information Page". Accessed in 2016-12-12.
External links
Source of the article : Wikipedia
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