LUPUS WHAT IS IT?
Lupus is a chronic inflammatory disease that can affect various parts of the body, especially the skin, joints, blood, and kidneys. The body's immune system normally makes proteins called antibodies to protect the body against viruses, bacteria, and other foreign materials. These foreign materials are called antigens. In an autoimmune disorder such as lupus, the immune system loses its ability to tell the difference between foreign substances (antigens) and its own cells and tissues. The immune system then makes antibodies directed against "self." These antibodies, called "auto-antibodies," react with the "self" antigens to form immune complexes. The immune complexes build up in the tissues and can cause inflammation, injury to tissues, and pain.
For most people, lupus is a mild disease affecting only a few organs. For others, it may cause serious and even life-threatening problems. More than 16,000 Americans develop lupus each year. It is estimated that 500,000 to 1.5 million Americans have been diagnosed with lupus.
TYPES OF LUPUS:
There are three types of lupus: discoid, systemic, and drug-induced.
Discoid (cutaneous) lupus is always limited to the skin. It is identified by a rash that may appear on the face, neck, and scalp. Discoid lupus is diagnosed by examining a biopsy of the rash. In discoid lupus the biopsy will show abnormalities that are not found in skin without the rash. Discoid lupus does not generally involve the body's internal organs. Therefore, the ANA test, a blood test used to detect systemic lupus, may be negative in patients with discoid lupus. However, in a large number of patients with discoid lupus, the ANA test is positive, but at a low level or "titer." In approximately 10 percent of patients, discoid lupus can evolve into the systemic form of the disease, which can affect almost any organ or system of the body. This cannot be predicted or prevented. Treatment of discoid lupus will not prevent its progression to the systemic form. Individuals who progress to the systemic form probably had systemic lupus at the outset, with the discoid rash as their main symptom.
Systemic lupus is usually more severe than discoid lupus, and can affect almost any organ or system of the body. For some people, only the skin and joints will be involved. In others, the joints, lungs, kidneys, blood, or other organs and/or tissues may be affected. Generally, no two people with systemic lupus will have identical symptoms. Systemic lupus may include periods in which few, if any, symptoms are evident ("remission") and other times when the disease becomes more active ("flare"). Most often when people mention "lupus," they are referring to the systemic form of the disease.
Drug-induced lupus occurs after the use of certain prescribed drugs. The symptoms of drug-induced lupus are similar to those of systemic lupus. The drugs most commonly connected with drug-induced lupus are hydralazine (used to treat high blood pressure or hypertension) and procainamide (used to treat irregular heart rhythms). Drug induced lupus is more common in men who are given these drugs more often. However, not everyone who takes these drugs will develop drug-induced lupus. Only about 4 percent of the people who take these drugs will develop the antibodies suggestive of lupus. Of those 4 percent, only an extremely small number will develop overt drug-induced lupus. The symptoms usually fade when the medications are discontinued.
Although drug-induced lupus and discoid lupus share features of systemic lupus, the rest of this brochure primarily discusses systemic lupus.
