Systemic Lupus Erythematosus (Lupus)


What Is It?

Systemic lupus erythematosus, commonly called lupus or sometimes SLE, is an autoimmune disorder, which means it is caused when immune defenses mistakenly attack the body’s own cells rather than protecting them from outside invaders. In lupus, immune proteins called autoantibodies target cells in many different parts of the body, causing inflammation and tissue damage in the joints, skin, kidney, nervous system (brain, spinal cord and nerves), blood, heart, lungs, digestive system and eyes. Autoantibodies also can attach themselves to specific body chemicals, forming abnormal molecules called immune complexes. When immune complexes deposit in various organs and tissues, they trigger additional inflammation and injury.

The exact cause of lupus remains a mystery, although scientists are investigating many different possibilities. Researchers believe several factors may play a role in the development of the disease. Since 90 percent of all lupus patients are women, usually of childbearing age, researchers think hormones may be involved. Lupus tends to run in families, so genetic factors may play a role. There is some evidence that the illness may be more common in people of African, Native American, West Indian and Chinese ethnic background. Some researchers think lupus may be triggered by a virus or another type of infection in people who are susceptible to the disease.

Lupus is relatively rare, affecting less than one in 2,000 people.


In some patients, lupus causes only mild illness, but in others it leads to potentially deadly complications. Its symptoms tend to come and go in a series of periods of intensified symptoms, called flares, followed by periods of decreased symptoms, called remissions. Flares can be triggered by many different factors, including sun exposure, infection, medication or possibly pregnancy, but often flares occur for no apparent reason.

Lupus has the potential to affect many different parts of the body, so it can cause a wide range of symptoms. They include:

  • Malaise (a generally sick feeling)
  • Fever
  • Loss of appetite
  • Weight loss
  • Muscle pain, with pain and swelling of the joints
  • A butterfly-shaped rash on the cheeks and bridge of the nose, called a malar rash
  • Skin photosensitivity (a more widespread rash and flulike symptoms after exposure to sunlight)
  • Hair loss
  • In about 20 percent of patients, a discoid rash, which appears as firm, round red plaques with raised borders
  • Painful ulcers in the mouth, nose and genital regions

Other possible symptoms of lupus include:

  • Neurological symptoms (headaches, seizures, trouble thinking or stroke)
  • Psychiatric symptoms (including psychosis, in which hallucinations occur)
  • Heart problems (abnormal heart rhythms, heart failure, inflammation of the heart muscle or lining)
  • Lung symptoms (especially pleurisy, which causes painful breathing)
  • Loss of vision
  • Pain or swelling in an extremity due to thrombosis (abnormal blood clots)

In contrast to systemic lupus erythematosus, which involves many organs, some people develop a form of lupus that involves only the skin, called cutaneous lupus or discoid lupus erythematosus. Another form of lupus follows exposure to certain drugs (drug-induced lupus) including procainamide (Procan SR, Promine, Pronestyl) and hydralazine (sold as a generic). While drug-induced lupus may cause rash, arthritis and fever that appear similar to the systemic form of lupus, it tends to be milder.


Your doctor will begin by reviewing your symptoms, your medical history and your exposure to factors that can trigger lupus flares. Next, he or she will examine you, looking for skin rashes on your face or on sun-exposed skin, tenderness or swelling of the joints, and ulcers inside your mouth or nose. Your doctor also will listen to your heart and lungs with a stethoscope, checking for signs of pericarditis (inflammation of the membrane covering the heart) or pleuritis (inflammation of the membranes covering the lungs).

If your doctor suspects you have lupus, he or she will order a blood test to look for a type of antibody, called the antinuclear antibody (ANA), that almost all people with lupus have in their blood. However, since the ANA test can sometimes be positive in people who do not have lupus, your doctor may order follow-up blood tests to look for other types of antibodies. Lupus cannot be diagnosed only on the basis of the ANA test.

Your doctor may evaluate your condition using the criteria established by the American College of Rheumatology. These criteria originally were formulated in 1982, and then updated in 1997. It is important to recognize that meeting the lupus criteria is not required for diagnosis, since they were established for research studies of lupus. Still, they may be a useful guide. If you have had four of the 11 lupus criteria at some time during the course of your illness, even if fewer than four actually are active at the time of diagnosis, you may be eligible for entry into a research study of lupus, and the diagnosis is more certain.

The lupus criteria include the following:

  • Malar rash
  • Discoid rash
  • Photosensitivity
  • Ulcers in the mouth or nose
  • Arthritis
  • Pericarditis, confirmed by physical exam or electrocardiogram (EKG), or pleuritis (confirmed by physical findings or chest X-ray)
  • Kidney disorder (confirmed by finding high levels of protein in the urine or other specific urine abnormalities, especially red cells suggesting inflammation in the kidney)
  • Neurological disorder, including seizures or psychosis (a serious psychiatric illness)
  • Blood disorder, including abnormally low levels of red blood cells (anemia), white blood cells (leukopenia), or platelets (thrombocytopenia)
  • Immune disorder — This is established by the finding of certain antibodies in the blood, which may include a positive anti-ds-DNA test, a positive anti-Sm test, a false-positive VDRL (a positive test for syphilis in someone who doesn’t have syphilis), or a positive antiphospholipid antibody test (an antibody associated with miscarriage or blood clots).
  • Abnormal ANA test result

Other tests that may be done to help diagnose lupus include:

  • Erythrocyte sedimentation rate (ESR), a blood test that indicates the presence of inflammation
  • Blood complement levels (proteins involved in immune function that may be low in active lupus)
  • A skin or kidney biopsy (taking a small tissue sample for laboratory examination)
  • Additional blood tests for autoantibodies

Expected Duration

Lupus is a long-lasting (chronic) condition, although there may be periods in which the illness is relatively inactive or even completely quiet.


Since doctors have not determined the cause of lupus, there is no way to prevent it. You may be able to prevent flares of the illness by avoiding exposure to the sun as much as possible and using sunscreen if you are going to be in the sun.


Lupus may be treated with several different types of medication, including:

  • Nonsteroidal anti-inflammatory drugs (NSAIDS), such as ibuprofen (Advil, Motrin and other brand names) or naproxen (Aleve, Naprosyn and others)
  • Antimalarials, such as hydroxychloroquine (Plaquenil), chloroquine (Aralen), or quinacrine
  • Corticosteroids, such as prednisone (Deltasone and others), hydrocortisone, methylprednisolone (Medrol and others), or dexamethasone (Decadron and others)
  • Immunosuppressives, such as azathioprine (Imuran), cyclophosphamide (Cytoxan, Neosar) or mycophenolate mofetil (CellCept)
  • Methotrexate (Rheumatrex, Folex, Methotrexate LPF)

When To Call A Professional

Call your doctor whenever you experience any of the symptoms of lupus, especially if you develop skin symptoms (malar or discoid rash, photosensitivity, ulcers in your mouth or nose), together with fatigue, fever, joint pain, poor appetite and weight loss.


Most people with lupus have a normal life span. However, life expectancy and quality of life vary widely depending on severity of illness. The outlook can be poorer if the disease has seriously affected the kidneys or brain, or has caused a low platelet count.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.