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Treatment

The patient should avoid exposure to the sun. Skin lesions should be treated with topical corticosteroids, but overuse of these preparations should be avoided.

Etiology and Pathology

SLE is classified as an autoimmune disease in which the body seems to be unable to maintain normal mechanisms of tolerance to autoantigens. Activation of T helper cells and B cells results in the production of autoantibodies that attack antigens in the cytoplasm and nucleus of cells and on the surface of blood cells. The exact cause of SLE is unknown: genetic defects, hormonal changes, infection, physical or mental stress, some drugs, immunizations, and environmental triggers (sunlight, UV light exposure) are possible predisposing factors. See: autoimmune disease; glomerulonephritis

Autoantibodies can react with autoantigens to form immune complexes in such large numbers that they cannot be completely excreted; the immune complexes may precipitate within blood vessels, producing inflammation at the site and disrupting the flow of blood and oxygen to tissues. These deposits are particularly damaging in the glomeruli. Autoantibodies also promote the destruction of cells by stimulating neutrophil and macrophage phagocytic activity, which increases cell destruction from trauma, infection, or drugs.

Diagnosis

In 1997, revised criteria for diagnosis of SLE were established. The diagnosis can be made if four or more of the following criteria are present, either at one time or sequentially: (1) butterfly rash; (2) raised, scaly discoid skin lesions; (3) abnormal titer of antinuclear antibodies seen by immunofluorescence; (4) other autoantibodies (anti-Sm; serological tests for syphilis); (5) pleuritis or pericarditis (together referred to as “serositis”); (6) hemolytic anemia, leukopenia (white blood cell count less than 4,000 mm³), lymphopenia (lymphocyte count less than 1,500/mm³), or thrombocytopenia of less than 100,000/mm³; (7) oral or nasopharyngeal ulcers; (8) nonerosive arthritis; (9) psychosis or seizures without other clear cause; (10) photosensitivity skin rash; and (11) proteinuria greater than 0.5 g/day or cellular casts in the urine.

Some drugs can cause a lupus-like syndrome; the most common of these are procainamide, isoniazid, and hydralazine. See: drug-induced systemic lupus erythematosus

Symptoms

The onset of the disease may be acute or insidious. Patients have a wide variety of clinical symptoms, signs, and laboratory findings, but anemia, thrombocytopenia, polyarthritis, (polyarthralgia) skin rashes, glomerulonephritis, fever, malaise, weight loss, fatigue, and low blood levels of complement are the most common. Other signs include pleuritis, pericarditis, myocarditis, neurological changes including behavioral changes and seizure activity (neural lupus), gastrointestinal ulcerations, Raynaud's phenomenon (present in about 20% of patients), and other problems caused by inflammatory changes of the blood vessels or connective tissue. Most patients are prone to infection.

Treatment

No cure for SLE exists, and complete remission is rare. About 25% of patients have mild disease, demonstrating only minor skin and hematological signs, and can be treated with nonsteroidal anti-inflammatory drugs for their arthritis symptoms and topical treatment (sometimes with corticosteroid creams) for skin lesions. Rashes may respond to antimalarials, e.g., hydroxychloroquine, but patients must be observed closely for the possibility of drug-induced retinal damage. Other treatments for skin rash include quinacrine, retinoids, and dapsone. Life-threatening and severely disabling conditions should be treated with high doses of corticosteroids and supplemental calcium to minimize osteoporosis, which may be an undesired side effect of long-term glucocorticoid use. Immunosuppressive drugs are used for severe exacerbations and to reduce steroid dosage.

Prognosis

The prognosis depends on which organ systems are involved, how severely they are damaged, and how rapidly the disease progresses. Ten-year survival rates are high (80%). Renal failure and infections are the most common causes of death.

Patient care

Patient education related to the disease, diagnostic procedures, and treatment is essential in lupus, as in any chronic disease. Ongoing assessment is carried out to assess flares of the illness. The purpose, proper dosage, use, and side effects of drugs is taught. Patients need emotional support to help cope with changes in appearance. Patients should be taught to wear clothing and hats that block direct sunlight, use a sunscreen with a 15 or higher protection factor, and to maintain a diet appropriate for their renal functional status. The health care professional should help establish a regimen for adequate relief of both the musculoskeletal pain and chronic fatigue experienced by most patients, encouraging adequate rest. Heat packs relieve joint stiffness and pain, and regular gentle exercise helps to maintain full range of motion. Physical and occupational therapy consultations are provided as appropriate. Additional support and teaching depend on the organ system most affected by the disease. If the female patient of childbearing age has no renal or neurologic impairment, she can have a safe, successful pregnancy if desired. Over time, patients with severe progressive disease need assistance in coping with chronic illness and the possibility of mortality. Referrals to the Lupus Foundation of America (202-349-1155; www.lupus.org) and the Arthritis Foundation (800-283-7800; www.arthritis.org) are helpful.