A woman in her 50’s developed a reddish purple rash on her eyelids which gradually spread to the face, neck and chest, and later to almost all other parts of the body within a few weeks time. It was accompanied by muscle weakness. The doctor diagnosed her condition to be dermatomyositis.
An inflammatory disease which is characterized by skin rash and muscle weakness is known as dermatomyositis. It is seen to occur in children between 5 years to 15 years of age, and in adults between late 40‘s to early 60’s. The symptoms develop gradually over a period of few weeks to few months.
The exact cause of dermatomyositis is not known and the factors that may cause it are still being researched. Some probable factors include genetic factors, autoimmune disorder, cancer, toxic and infectious agents and certain drugs like penicillamine, statins, hydroxyurea, phenylbutazone, and quinidine.
A few common dermatomyositis symptoms are:
Other symptoms include
One of the complications include the weakness of the muscles of the esophagus due to which there will be difficulty in swallowing food (dysphagia) and may result in malnutrition and weight loss. Due to dysphagia, the liquids, foods and saliva that one takes may enter into the lungs leading to pneumonia. Ulcers can form in the stomach and intestines causing them to bleed. There is an increased risk of developing infections in the digestive and respiratory tracts. Calcium deposits occur in the connective tissue, skin and muscles which is known as calcinosis.
Medical conditions that occur due to dermatomyositis are
The main diagnostic symptom is the characteristic rash that occurs in dermatomyositis. The cross sectional images of the muscles are obtained from MRI scan (magnetic resonance imaging) which uses a magnetic field and radio waves to generate images. With MRI, the doctor can detect calcification, fibrosis, swelling of muscles and pattern of muscle weakness.
The doctor may conduct an electromyography in which electrical activity is measured when the patient tightens and relaxes the muscle. The test is positive for a muscle disease if there are changes seen in the pattern of electrical activity. The distribution of the disease can also be determined by testing the different muscles through electromyography.
A small sample of the muscle is taken (biopsy) and analyzed which helps in detecting damage, infection, swelling of muscles, enzyme deficiencies, and abnormal proteins.
A blood test is done to know the levels of muscle enzymes like aldolase, creatinine and to detect antibodies that are specific to dermatomyositis. An increased level of muscle enzymes indicates damage of muscle. A skin biopsy may also be done to diagnose dermatomyositis.
The treatment for dermatomyositis is aimed at improving the strength and function of the muscle. To suppress swelling of the muscle and to reduce the production of antibodies, corticosteroids like prednisone are given. Improvement is seen in 2 to 4 weeks but the medication needs to be taken for years. Topical application of corticosteroids on the skin is also recommended .To counteract the adverse effects (disturbance in sleep, weight gain, appetite increase and psychological problems) caused by corticosteroids, the doctor prescribes biphosphonates such as risedronate, zoledronic acid, alendronate, and supplements like Vitamin D and calcium.
To improve the symptoms of interstitial lung disease and dermatomyositis, immunosuppressant drugs like cyclosporine (sandimmune,neoral) and cyclophosphamide (cytoxan).
Antimalarial medication like chloroquine (aralen) and hydroxychloroquine (plaquenil) is taken to relieve pain, over the counter medications like acetaminophen (Tylenol), ibuprofen (motrin, advil) and aspirin can be taken.
Antibodies are taken from blood donors and are given intravenously that help in counteracting the antibodies that attack the skin and muscle in dermatomyositis.
A transplant rejection drug known as Tacrolimus (Prograf). To improve muscle strength and reduce the symptoms of rash drugs like Rituximab (Rituxan) is given. When the calcium deposits become extremely painful, surgery to remove them is recommended.
Speech therapy is given to patients who have developed weakness in the muscles of the jaw and have difficulty in swallowing.
To improve the strength and flexibility of the muscles, a physical therapist teaches the patient exercises that can help improve his muscle condition. Since chewing and swallowing becomes difficult in dermatomyositis, the dietician shows the patient how to prepare easily chewable foods.
There is no specific way to prevent dermatomyositis, but one can develop strong and flexible muscles by exercising regularly. An exercise program must be made after consulting the physical therapist. The skin should be protected from sunlight by wearing protective clothing and applying a sunscreen lotion.