- Antinuclear antibody (ANA) – A type of antibody directed against the nuclei of the body’s cells. Because these antibodies can be found in the blood of children with lupus and some other rheumatic disorders, testing for them can be useful in diagnosis.
- Corticosteroids – Powerful anti-inflammatory hormones made naturally in the body or synthetically for use as medicine. Corticosteroids may be taken by mouth or intravenously, or they may be injected into the affected joints to temporarily suppress the inflammation that causes arthritis-related swelling, warmth, loss of motion, and pain.
- Disease-modifying antirheumatic drugs – A class of medication that can slow or potentially stop the activity of rheumatic disorders, such as rheumatoid arthritis, often by suppressing the overactive immune system.
- Erythrocyte sedimentation rate (ESR or sed rate) – A test that measures how quickly red blood cells fall to the bottom of a test tube of unclotted blood. Rapidly descending cells (an elevated sed rate) indicate inflammation in the body.
- Flare – A period in the course of disease in which symptoms become worse.
- Immune response modifiers – A relatively new class of medications used in arthritis treatment that are based on compounds made by living cells. These compounds modify the action of the immune system by blocking chemicals that fuel inflammation and tissue destruction.
- Juvenile arthritis (JA) – A term often used to describe arthritis in children.
- Juvenile idiopathic arthritis (JIA) – A term for various types of chronic arthritis in children. Arthritis is an inflammation of the tissues lining the joints of the body. JIA can cause swelling, pain, damage to the joints, and, in some cases, damage to other parts of the body. Juvenile idiopathic arthritis has replaced juvenile rheumatoid arthritis as the preferred term for the same condition.
- Juvenile rheumatoid arthritis (JRA) – A term used to describe the most common types of arthritis in children. It is characterized by joint pain, swelling, tenderness, warmth, and stiffness that lasts for more than 6 weeks and cannot be explained by other causes. Previously, juvenile rheumatoid arthritis was the preferred term, but recently it has been replaced by juvenile idiopathic arthritis.
- Nonsteroidal anti-inflammatory drugs (NSAIDs) – A class of medications that work to reduce pain, fever, and inflammation by blocking substances called prostaglandins. Some NSAIDs, such as ibuprofen (Motrin) and naproxen sodium (Aleve), are available over the counter, while many are available only with a doctor’s prescription.
- Oligoarthritis (formerly known as pauciarticular juvenile rheumatoid arthritis) – Refers to a form of JIA that affects four or fewer joints.
- Pericarditis – Inflammation of the pericardium, the membrane that surrounds the heart. Pericarditis is a feature of some rheumatic disorders, including systemic arthritis.
- Pleuritis – Inflammation of the pleura, the membrane that covers the lungs and lines the inner chest wall. Pleuritis is a feature of some rheumatic disorders, including systemic arthritis.
- Polyarthritis (formerly known as polyarticular juvenile rheumatoid arthritis) – Refers to a form of JIA that affects five or more joints.
- Remission – A period when symptoms of a condition improve or disappear completely. Sometimes remission is permanent, but more often it is punctuated by flares of the disease.
- Rheumatic disorders – Disorders that affect the joints and soft tissues, causing pain, and sometimes inflammation, tissue damage, or disability.
- Rheumatoid factor – An antibody that is found often in the blood of adults with rheumatoid arthritis. Testing for the antibody may be useful as a diagnostic tool.
- Systemic – Refers to a disease that can affect the whole body, rather than just a specific organ or joints. For example, the JIA subtype systemic arthritis (formerly known as systemic juvenile rheumatoid arthritis) can affect the skin, blood vessels, bones, and membranes lining the chest wall, as well as the joints.
- Tendonitis – The inflammation of tendons, which are strong bands of connective tissue that attach muscles to bones.
- Vasculitis – Inflammation of the blood vessels. Vasculitis is a feature of a number of rheumatic disorders.