Click here to view next page of this article Systemic Lupus ErythematosusSystemic lupus erythematosus is a multisystem disease that affects predominantly women between the ages of 16 and 55 years, especially African-American and Asian women. The exact etiology of systemic lupus erythematosus remains unknown, although the manifestations are attributed to the presence of multiple autoantibodies. Examples include antibodies directed against cell surface antigens on erythrocytes, leukocytes, and platelets, which result in increased clearance by the reticuloendothelial system and subsequently anemia. The clinical manifestations of systemic lupus erythematosus can be highly variable. At initial presentation, the most common features are fever, arthralgia and myalgias (typically asymmetric and migratory), butterfly rash, and photosensitivity. Also common are painless oral ulcerations and rashes, including discoid rash and a discrete, rounded, slightly scaling plaque on the face, scalp, extremities, and ears. During the course of disease, arthritis is the most frequent feature, occurring in approximately 76-88% of patients. The pattern of symmetric, inflammatory joint involvement, including multiple large and small joints such as those of the hand, wrists, ankles, and feet, mimics and can be confused with rheumatoid arthritis. Other major organ systems are commonly involved, and it is these systems that are a major determinant of the course and prognosis of systemic lupus erythematosus. American Rheumatism Association Criteria for Systemic Lupus Erythematosus
Screening with antinuclear antibody is useful, as its presence is predictive of a 1:3 to 1:6 risk of systemic lupus erythematosus, whereas its absence is associated with a 1:1,000 risk. Specific autoantibodies with greater positive predictive value for the systemic lupus erythematosus include anti-ds DNA (95% positive predictive value), anti-Sm (97% positive predictive value), anti-RNP, anti-Ro (SS-A), and anti-La (SS-B). Assessment of complement levels provide information regarding disease. Clinicians generally use the American Rheumatism Association classification for the diagnosis of systemic lupus erythematosus. The presence of a positive antinuclear antibody titer alone is not sufficient to diagnose lupus. Presence of four of the findings listed is associated with a 96% sensitivity and specificity for systemic lupus erythematosus and is accepted as diagnostic. Treatment begins with reassurance that systemic lupus erythematosus is not necessarily a life-threatening illness and with institution of prophylactic measures such as potent sunscreens or avoiding excessive sun exposure in photosensitive patients. Antimalarial agents such as hydroxychloroquine often are added in patients with refractory arthritis, cutaneous disease, or serositis. Systemic steroids in low doses are used for arthritis or mild pleuropericarditis and are used in high doses for major organ involvement (eg, nephritis) or vasculitis. Immunosuppressive drugs such as azathioprine or cyclophosphamide may be required for patients. High-dose steroids and cyclophosphamide are the preferred regimen for diffuse proliferative glomerulonephritis. Use of cyclophosphamide in treatment of lupus nephritis has been associated. Oral contraception may be used by patients with systemic lupus erythematosus. Disease symptoms should be quiescent for 6 months. |