Lupus is an autoimmune disease. The role of the immune system is to fight foreign substances in the body, like bacteria and viruses. In autoimmune diseases, however, the immune system is out of control and attacks healthy tissues, not foreign substances.
There are three main types of lupus:
- Systemic lupus erythematosus is the most common form. It's sometimes called SLE, or just lupus. The word "systemic" means that the disease can involve many parts of the body, such as the heart, lungs, kidneys, and brain. SLE symptoms can be mild or serious.
- Discoid lupus erythematosus mainly affects the skin. A red rash may appear, or the skin of the face, scalp, or elsewhere may change color.
- Drug-induced lupus is triggered by a few medicines. It's like SLE, but symptoms are usually milder. Most of the time, the disease goes away when the medicine is stopped.
Plaquenil is approved to treat SLE and discoid lupus and should be used only when other lupus medications that are less likely to cause serious side effects have failed.
Rheumatoid arthritis is also an autoimmune disease. Similar to other autoimmune diseases, scientists still do not know the cause or causes of rheumatoid arthritis. There are many rheumatoid arthritis symptoms, including chronic pain along with tender, warm, and swollen joints. When used to treat rheumatoid arthritis, Plaquenil usually takes quite awhile (often several months) to reach its full effectiveness. If no improvement is seen within six months, however, Plaquenil probably is not going to work. Plaquenil should be used only when other rheumatoid arthritis medications that are less likely to cause serious side effects have been tried.