Lupus, also called systemic lupus erythematosus (SLE), is a chronic inflammatory condition that can affect any part of the body, including the skin, joints, kidneys, heart, lungs, and nervous system. It is one of the most common autoimmune diseases (diseases in which the immune system attacks its own body tissues).
Lupus is an unpredictable lifelong condition that typically affects young women between 18 and 40 years of age, but it can affect men and those older or younger. The ratio of women to men in the 15 to 40 age group is 12:1. Lupus occurs in 1 in 10,000 men, 1 in 1,000 white women, and 1 in 250 African American women.
In the early days of treating lupus, doctors only recognized the most severe cases and there were very limited treatments. As a result, the rates of survival were dismal. Today, doctors usually recognize cases much earlier and many more cases that are mild, and they now have improved ways of managing the disease. As a result, while there is still no cure for lupus, the survival rate is now close to 90% 10 years after diagnosis.
But available treatments all have risks and side effects, so people with lupus sometimes have to choose between those risks and the effects of their disease. In some cases, the disease is more moderate and minimal treatment is needed.
It's generally believed that lupus is caused by alterations in the immune system. The body's immune system normally fights foreign bacteria and viruses. But with lupus, the immune system may fail to recognize "self" substances and will make antibodies that attack the body's own tissue. This is called autoimmunity.
The exact cause of lupus is still unknown. Multiple factors are involved in the development of the disease, including heredity and environmental factors. It is recognized that sunlight causes symptoms to flare up. Other triggers include viral infections, the stress of illness, sometimes pregnancy, and certain medications. Because more women are affected than men, another theory suggests there is a relationship to estrogens.