Glossary

  • Alternative therapy: any therapy used in place of conventional or more traditional treatments. Examples are specialized diets instead of chemotherapy for cancer patients and herbal remedies in place of pharmaceutical medicines. [See complementary therapy.]
  • Amyopathic dermatomyositis: [see also dermatomyositis sine myositis] dermatomyositis with only skin symptoms, like the skin rash, and no muscle weakness or pain. The words break down to derma or skin, myo or muscle, itis or inflammation, sine or without. Therefore, DM sine myositis means the skin involvement without muscle inflammation.
  • Antibody: protein produced by the body that acts against antigens (substances foreign to the body) in the immune response. In a typical immune response, lymphocytes of the immune system identify the antigens as invaders and stimulate the formation of antibodies to react with the foreign cells and render them harmless.
  • Antigen: foreign protein that stimulates an immune response in the body.
  • Anti-Jo-1 antibody: protein associated with a higher incidence of interstitial lung disease. This autoantibody is found in about 25 percent of myositis patients.
  • Antirheumatic: type of medicine that acts against diseases with inflammation or pain in muscles or joints. Methotrexate and hydroxychloroquine (Plaquenil) are antirheumatic treatments.
  • Arthritis: inflammation or swelling of the joints.
  • Aspiration: inhaling or breathing in food or other substances into the larynx below the vocal chords toward your lungs. This can lead to aspiration pneumonia, an often serious infection in the lungs caused by these bits of inhaled substances. [see Silent aspiration.]
  • Autoantibody: protein of the immune system that acts against your own tissues.
  • Autoimmune disease: disease in which the body's immune system, which normally fights infections and viruses, is misdirected and attacks the body's own normal, healthy tissue through inflammation (swelling).
  • Biologic agent: product used to prevent or treat disease. Etanercept (Enbrel) and infliximab (Remicade) are biologics that target tumor necrosis factor proteins involved in inflammation.
  • Biopsy: removal and study of tissue to help decide what is wrong. Skin and muscle biopsies help doctors learn more about your condition.
  • Calcinosis: hard, often painful lumps or sheets of calcium that form under the skin's surface, especially in juvenile dermatomyositis.
  • Cataract: clouding over the lens of the eye that blocks light and distorts vision. Cataracts can be a side effect of prednisone and other medicines used to treat myositis. Regular eye exams are encouraged.
  • Chimerism: presence of non-self cells, derived from the mother, in a child's circulation. Bidirectional trafficking, or exchange of cells from mother to fetus and fetus to mother, is common during pregnancy. Microchimerism refers to the low levels of non-self cells.
  • Complement: network of many blood proteins that recognize and attack cells with antibodies. Eculizumab is a complement inhibitor with some success in a trial treating a dermatomyositis patient. More studies are needed to better understand the role of complement in myositis.
  • Complementary therapy: treatment used in addition to treatments prescribed by your doctor. Massage, sun protection, vitamin supplements, tai chi and aromatherapy are examples of what some myositis patients do or take in addition to the more traditional medicines. [See alternative therapy.
  • Conventional therapy: traditional treatments that are more commonly prescribed by physicians. For many people with myositis, for instance, conventional therapy includes prednisone and/or methotrexate.
  • Contracture: stiffening of the joint, causing it to shorten and stay bent.
  • Corticosteroids: medicines aimed to slow the immune system and stop the inflammatory attack on skin, muscle and other body systems. These medicines are also used to relieve redness, swelling, itching, and discomfort. Prednisone and methylprednisolone are two types of corticosteroids.
  • Disease activity: what is currently and actively going on with the disease, i.e. muscle weakness and skin rash. [See disease damage.]
  • Disease damage: long-term effects or changes caused by the disease or medicine's side effects and not by current disease activity. [See disease activity.]
  • Distal: located away from the center of the body. [See also proximal.] In terms of muscles, distal muscles refer to those in the fingers, hands, and feet.
  • Dysphagia: trouble swallowing; trouble moving food or liquid from your mouth to your stomach.
  • Dysphonia: problems with the voice, often resulting in weaker or hoarse sounds.
  • Electromyogram: test using small needles inserted in muscles to measure the electrical activity of skeletal muscle as you relax and as you tighten the muscle. Noting changes in the electrical activity pattern helps determine whether you have a muscle disease. This test is typically used to support the findings of myositis and not to make the initial diagnosis.
  • First-line treatment: medicine that a doctor chooses to try as the initial or first treatment for your condition.
  • Flare: return of past symptoms or increase in current symptoms after a period of remission or slower disease activity. Flares can occur when tapering medicine too quickly or overexerting yourself through exercise or stress. People with dermatomyositis might notice flares when they have been exposed to sunlight.
  • Flow cytometry: blood test looking at a specific group of white blood cells (lymphocytes) that is used to learn more about the extent and severity of juvenile myositis. An abnormality in proportions of different types of lymphocytes is often seen in children with untreated juvenile dermatomyositis.
  • Gottron's papules: [also called Gottron's sign] bumps found over the knuckles, elbows and knees, often with a raised, scaly break-out. Gottron's papules are characteristic of both adult and juvenile dermatomyositis.
  • Heliotrope rash: bluish-purple discoloration (like the color of the heliotrope flower) around the eyes, especially the upper eyelids, often with swelling.
  • Idiopathic: of unknown cause. Idiopathic inflammatory myopathy is the broader medical term used to describe all forms of myositis.
  • Immune response: the body's response to a foreign substance in order to keep it from harming the body. Inflammation or swelling is one type of immune response.
  • Immune system: your body's system that protects you from foreign substances (bacteria, viruses, etc.) through an immune response. In myositis, the immune system is thought to be overactive, causing immune cells to attack your body's own healthy tissue. The immune response in this case is inflammation or swelling.
  • Immunosuppressant: medicine used to slow the body's immune system in an attempt to keep it from mistakenly fighting healthy tissues. These medicines lower the body's ability to fight infection.
  • Inflammation: a basic and typical response to injury that results in redness, swelling, and pain. The immune system responds to foreign invaders through inflammation, normally leading to repair and healing. Inflammation can also result in some loss of function.
  • Integrative therapy: combination of complementary therapy used to treat symptoms and conventional therapy used to treat underlying disease.
  • Interstitial lung disease: swelling of the lung that can cause scarring, eventually affecting a person's ability to breathe. Lung scarring is typically irreversible.
  • Intravenous: method of giving medicine through a needle directly into your vein. This allows the medicine to get into your system and begin working quicker than swallowing pills or liquids.
  • Intravenous immune globulin (IVIG): [Also called intravenous immunoglobulin, intravenous gamma globulin, IGIV] treatment in which blood proteins or antibodies are introduced into the body through a needle giving the medicine into a vein over a period of time. The immune globulin, from pooled blood taken from many donors, temporarily replaces the antibodies (immunoglobulins), but repeat infusions are required to maintain adequate levels. The high cost of treatment is often prohibitive and not all insurance companies cover this therapy for myositis patients.
  • Intravenous port: device that remains in your vein to make giving medicines by needle less painful or uncomfortable.
  • Lipodystrophy: disorder of fat metabolism, especially a loss of fat.
  • Local: affecting only a part of the body. Local treatments include topical creams for the skin rash of dermatomyositis.
  • Lymphocyte: cell, originating from stem cells, that plays a role in immunity.
  • Magnetic resonance imaging (MRI) scan: test that uses a powerful magnet to create computer pictures of muscles to show possible inflammation.
  • Maintenance dose: small amount of medicine a person requires in order to keep symptoms from returning or worsening.
  • Malar rash: flat or raised butterfly-shaped rash across the cheeks and bridge of the nose. The rash is red and can appear blotchy. The malar rash is also characteristic of lupus.
  •  Manual muscle testing (MMT): test of a person's muscle strength, or ability of the muscle to move a part of the body against resistance. A doctor or therapist will assess muscle strength in individual muscles, and the results show which muscles are weak and the pattern of the weakness. MMT is often performed throughout the disease course to follow the patient's progress over time.
  • Mechanic's hands: dilated capillary loops at the base of the fingernails with irregular, thickened and distorted cuticles, or cracked, dirty-looking horizontal lines at the sides and palms of the fingers.
  • Mixed connective tissue disease (MCTD): autoimmune disorder in which there are signs and symptoms of other connective tissue diseases, especially lupus, scleroderma and polymyositis.
  • Monoclonal antibodies: antibodies from a single cell, in large numbers, that act against a particular antigen. Etanercept (Enbrel) and infliximab (Remicade), for example, target tumor necrosis factor (TNF), a protein that is believed to increase in myositis patients.
  • Muscle enzymes: proteins found in muscle tissue cells. When the muscle tissue cells are injured (like they are through the inflammation of myositis), the cells break open and leak enzymes into the bloodstream. Blood tests are used to measure the levels of these enzymes in the blood to help doctors determine what may be happening and also how well you are responding to treatment.
  • Myositis-associated autoantibodies: proteins found in the blood of myositis patients as well as in the blood of patients with other autoimmune diseases. These autoantibodies are not specific to myositis. [See myositis-specific autoantibodies.]
  • Myositis-specific autoantibodies: proteins found only in the blood of myositis patients, therefore these autoantibodies are specific to myositis. Anti-Jo-1 and anti-SRP are myositis-specific autoantibodies. [See myositis-associated autoantibodies.]
  • Nailfold capillary study: study of the small blood vessels at the base of the fingernail in patients with dermatomyositis. Pictures of the nailfold are often taken over time to note changes that give clues as to how you are responding to treatment. Dilated, uneven capillaries, instead of evenly spaced loops, are related to how severe the weakness and rash are.
  • Neopterin: a test of the immune system that shows elevated levels of this macrophage (immune system cell) in patients with persistent muscle damage.
  • Occupational Therapy: therapy designed to restore or maintain a patient's ability to perform tasks used in daily living, often through developing ways to modify or adapt activities.
  • Osteopenia: condition of thinning bones.
  • Osteoporosis: disease marked by decreased bone mass and density resulting in thinning, weakened bones.
  • Overlap syndrome: diagnosis made when a patient has more than one autoimmune disease. The patient's symptoms must meet the diagnostic criteria of all of the diseases to be considered overlap. Some common overlaps are rheumatoid arthritis, lupus, scleroderma and Sjogren's.
  • * Physical Therapy: [also physiotherapy] treatment of a disease through physical activity with goals of restoring and/or maintaining functional activities.
  • Proximal: located toward the center of the body, like muscles of the neck, stomach, upper arms and upper legs. [See distal.]
  • Pulse: dose of medicine given intravenously (through IV needle) over a short period of time. This is often a high dose of the medicine to "jump start" therapy.
  • Range-of-motion exercises: type of exercise that focuses on maintaining flexibility and movement in the joints. This is often the first type of exercise therapy used, with more stretching and strengthening exercises added as the patient is ready.
  • Refractory: unaffected by treatment; resistant or unresponsive to treatment. In refractory cases of myositis, the medicines used do not ease the symptoms or the disease.
  • Relapse: return of symptoms after a period of remission or stable disease activity.
  • Remission: period of time when a patient shows no symptoms of disease and has been off all medicines for six months or longer.
  • Retrospective: type of study that looks at patients' past experiences to determine if a certain treatment is working.
  • Rheumatic disease: condition involving inflammation and pain in muscles and joints.
  • Second-line treatment: medicine chosen after a patient fails to respond to the first-line medicine given or when side effects from the first medicine outweigh the benefits. Methotrexate is often a second-line treatment after initial treatment with prednisone.
  • Shawl sign: flat red rash on the back and across the shoulders.
  • Side effects: unwanted reaction to a medicine. For example, weight gain is a common side effect of corticosteroids.
  • Sign: objective evidence or finding of a disease that can be seen and understood by a doctor.
  • Silent aspiration: occurs when foods or liquids are breathed into the lungs but do not produce the typical reaction of coughing. With silent aspiration, people do not realize they are breathing in particles of their food.
  • Staph infection: bacterial (staphylococcus aureus) infection that grows deep below the skin. This bacteria usually enters the skin through open cuts.
  • Steroid myopathy: [also called type 2 muscle fiber atrophy] weakness caused by long-term use of corticosteroids.
  • Symptom: subjective evidence or personal findings of a disease as experienced and recognized by the patient.
  • Systemic: affecting the body as a whole. Systemic medicines like prednisone are taken orally or intravenously and affect more than one part of the body. [See local.]
  • Taper: process of slowly lowering your dosage of medicine to reach a maintenance dose or to stop taking the medicine altogether. It is important to taper certain medicines—corticosteroids in particular—to give your body adequate time to adjust to the change and begin producing its own hormone.
  • Tumor necrosis factor (TNF): immune cell protein that kills cells that appear abnormal and stimulates autoimmune reactions like inflammation. TNF blockers include infliximab (Remicade) and etanercept (Enbrel).
  • Ulceration: break in the skin or mucous membrane.
  • Vacuoles: holes in the muscle fibers evident in muscle biopsies of inclusion-body myositis (IBM) patients.
  • Vasculitis: swelling of blood vessels under the skin that causes a visible rash.
  • von Willebrand factor antigen: blood test that shows damage to the lining of the blood vessels and may help doctors check the degree of the problem to decide on the right treatment plan. This test may be used to monitor the disease in children with myositis.

 

 

Updated March 2012

 
 

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