Systemic lupus erythematosus (SLE) is a chronic inflammatory disease affecting connective tissue of the skin, joints, kidneys, nervous system, and mucous membranes. Unlike the more common type, discoid lupus erythematosus (DLE), which affects exposed areas of the skin, the more serious and potentially fatal SLE can affect any organ system in the body. The disease is marked by spontaneous remissions (periods when the symptoms lessen or disappear without a known cause) and relapses (periods when the symptoms return or flare). The disease ranges in severity from a mild disorder to a rapidly progressing fatal illness. Severity of symptoms also vary, not only between individuals, but within the same individual over time.
The exact cause of SLE is unknown. It is an autoimmune disorder, in which the body's defense system mistakenly attacks its own connective tissue, causing painful inflammation. The prevalence of SLE is influenced by many factors, including gender, race, and heredity. About 85% of those diagnosed with lupus are women. Sex hormones appear to play some role since most cases develop during the childbearing years. In the US, black and Asian women appear to be at increased risk. Other family members often have SLE or other connective tissue disorders. First-degree relatives of individuals with SLE are at increased risk, and although they may not have any symptoms, they often carry the autoantibodies (antibodies which react against the individual's own body tissue).
Individuals using certain medication may develop a lupus-like syndrome. The drugs most frequently responsible are antihypertensives (for high blood pressure), cardiac depressants (for irregular heart rhythms), and tuberculostatics (for treatment or prevention of tuberculosis). Symptoms of drug-induced lupus are generally milder, affect men and women equally, and fade when the drug is discontinued.
Joint and muscle pain are often the earliest symptoms of SLE.
Most individuals will complain of a skin rash at some time, particularly after exposure to sunlight. The characteristic red, blotchy, butterfly-shaped rash over the cheeks and bridge of the nose occurs in about 50% of the cases.
Temporary hair loss may occur, but there is no scarring and the hair grows back between attacks.
Raynaud's syndrome (in which the fingers turn from white to blue, and finally red) is common on exposure to cold or during periods of stress.
Anxiety and depression are very common, due to stress and the uncertainty of having a chronic, potentially serious disease.
Visual disturbances may occur, including over-sensitivity to light (photophobia) or blurred vision.
Other symptoms include fever, weight loss, loss of appetite (anorexia), abdominal pain, headaches (muscle tension or migraine), or a general feeling of ill health (malaise).
Physical exam: Systemic lupus erythematosus may present with butterfly facial rash, ulcers in the mouth, hair loss, and red, swollen painful joints. If more systems are involved, symptoms are related to inflammation in the involved organs. Common findings include pleurisy (inflammation of the lining of the lungs) and pericarditis (inflammation of the membrane surrounding the heart). Scattered abdominal tenderness is most often due to sterile peritonitis (inflammation of the membrane lining the abdominal cavity that is not caused by an infectious organism). High blood pressure (hypertension) and ankle swelling (peripheral edema) are the most common indications of kidney involvement (renal disease). Symptoms of drug-induced lupus are similar but milder than SLE.
Tests: No one test can determine lupus.
Anemia, detected on a complete blood cell count (CBC) may be caused by chronic inflammation, renal disease, or hemolysis (destruction of red blood cells). Increased urea nitrogen or creatinine on a blood chemistry, or an abnormal urinary sediment indicates kidney involvement.
Blood tests used to detect specific antibodies include ANA (antinuclear antibody test), the anti-DNA antibody test, the anti-Sm antibody test, and complement levels.
Skin biopsy (removal of tissue for microscopic examination) can also detect antibodies that occur when the disease is active.
X-rays of painful joints, muscle testing through electromyography (EMG), and microscopic examination of fluid withdrawn from the joints may be done to rule out other disease processes.
Once the diagnosis has been established, specific organ involvement should be assessed. This is particularly important with regard to kidney disease.
How is SLE treated?
There is no cure for Systemic lupus erythematosus. Treatment is aimed at reducing inflammation and relieving symptoms. Any drug that may have triggered the condition should be withdrawn, if possible. Individuals whose symptoms are made worse by sunlight should avoid exposure to sunlight and should use sunscreen. The skin rash can often be effectively treated with antimalarial drugs. Lupus arthritis (inflammation of the joints) is treated with nonsteroidal anti-inflammatory (NSAID) drugs, DMARDs or antimalarial drugs. Lupus myositis (inflammation of the muscles) may be treated with corticosteroids and an effective exercise program. Corticosteroid drugs may be prescribed for fever, pleurisy, pericarditis, and neurological symptoms. Cytotoxic (anticancer) drugs are reserved for serious systemic involvement, especially when corticosteroids have been tried but are ineffective. Psychological needs must be addressed, as emotional support is especially important.
Drug-induced lupus usually only requires the withdrawal of the offending medication.
What might complicate it?
Possible complications include serious impairment of vital organs such as lungs, heart, brain, or kidneys. Opportunistic infections (infections that occur due to an impaired physical state) are a leading cause of death.
The outlook for individuals with SLE has improved dramatically, although if the kidneys are affected, the disease may still be life threatening. The ten-year survival rate is now 80% to 90%. Factors leading to this improved prognosis include a more accurate diagnosis, faster and more effective treatment, dialysis for treatment of kidney failure is routinely available, and the antibiotics available are now more effective in treating infectious complications. In most individuals, the illness pursues a mild, chronic course, occasionally interrupted by relapses of disease activity. For many, the disease may only affect a few organs.