Systemic lupus erythematosus, also commonly referred to as lupus or SLE, is a chronic, inflammatory, autoimmune disease. Lupus can affect the joints, skin, kidneys, lungs, heart, nervous system and other organs of the body. It is not uncommon for symptoms associated with lupus to resemble symptoms associated with other types of arthritis and rheumatic disease, making lupus difficult to diagnose.
Several types of lupus exist:
- Systemic lupus erythematosus
- Discoid lupus
- Subacute cutaneous lupus erythematosus
- Drug-induced lupus
- Neonatal lupus
It is known that lupus is an autoimmune disease, meaning the immune system attacks a person's own cells and tissues. The reason for the immune system malfunction is not completely understood but as is the case with rheumatoid arthritis, scleroderma, and other autoimmune diseases, it is thought to involve genetic factors and environmental factors.
Symptoms which help doctors differentiate lupus from other rheumatic diseases include:
- A butterfly-shaped rash appearing on the cheeks and over the bridge of the nose (malar rash)
- Scaly sores appearing on the face, neck, and chest (discoid rash)
- Photosensitivity (sensitivity to sunlight)
- Mouth ulcers
- Arthritis pain and joint stiffness
- Serositis - Inflammation of tissues which line the lungs, heart, abdomen, and internal organs
- Kidney problems
- Central nervous system abnormalities
- Blood abnormalities
- Antinuclear antibodies
- Immune system problems
Fatigue, fever, swollen glands, and weight loss may occur with lupus.
There is no single test used to diagnose lupus. Diagnosis is based on a combination of factors (clinical symptoms, blood tests, and medical history) which together provide evidence of abnormalities in several organ systems. Laboratory tests and x-rays are used to confirm the diagnosis of lupus.
Besides abnormalities which may be revealed by routine blood counts, chemistry tests, and urinalysis, tests which are specifically relevant to lupus include:
- Sedimentation rate and CRP
- Antinuclear antibody test
- Specific antibodies (anti-dsDNA, anti-smith, anti-phospholipid)
- Complement test
Treatment of lupus depends on the severity of symptoms and organ systems involved. NSAIDs (nonsteroidal anti-inflammatory drugs) are commonly prescribed to control inflammation. Plaquenil which is used as a DMARD (disease-modifying anti-rheumatic drug) is another commonly prescribed medication used to treat lupus, as are other immunosuppressants including Imuran, Cytoxan, cyclosporine, and CellCept.
Corticosteroids (e.g. prednisone) are also used to treat the condition.
Studies are currently ongoing which are testing the effectiveness of new treatments for lupus, most of which are monoclonal antibodies.
Lupus affects 10 times more women than men. Though lupus can develop at any age, disease onset usually occurs between the ages of 18 and 45 years old. African-Americans and Asians have a higher risk of developing lupus than people of other racial or ethnic backgrounds. The Lupus Foundation of America estimates that 1.5 million Americans have one of the types of lupus, but that estimate actually may be low.
- Systemic lupus erythematosus (SLE), as its name suggests, can involve multiple organ systems and is the most serious type.
- Discoid lupus erythematosus affects only the skin and does not involve other organ systems.
- Drug-induced lupus is caused by a reaction to certain prescription medications. Symptoms resemble SLE but it does not affect the central nervous system or kidneys.
- Subacute cutaneous lupus erythematosus causes skin lesions to appear on parts of the body exposed to the sun.
- Neonatal lupus is a rare disease which affects newborn babies.
- Nearly all lupus patients are positive for antinuclear antibodies.
