Systemic Lupus Erythematosus (SLE)
The manifestations are protean, and there is no characteristic or pathognomonic finding. Instead, this disease is diagnosed by finding suggestive
serologic and clinical findings. Findings may include:
Skin rash - malar or discoid
Sensitivity to light (photodermatitis)
Serositis - inflammation of serosal surfaces along with effusions
Glomerulonephritis - the worst problem with SLE
Cytopenias - anemia, leukopenia, thrombocytopenia
Antinuclear antibody - rim pattern, anti double stranded-DNA and anti-Smith autoantibodies are most specific for SLE
Arthralgias, myalgias
Vasculitis - anywhere: CNS, skin, kidney, etc
Decreased serum complement - especially C1q
Thrombosis - in arteries or veins
Genetic factors: tends to run in families; association with HLA Dr-2 and
Dr-3; more common in young women (especially African-American).
Drugs can produce "drug-induced" SLE: list includes procainamide,
hydralazine, isoniazid, d-penicillamine.
Discoid lupus erythematosus (DLE): a benign disease with skin involvement;
ANA positive in only a third (but some of these go on to SLE).
Mixed Connective Tissue Disease (MCTD)
A wastebasket category for patients who do not clearly fit into other
categories. There are features similar to SLE, scleroderma, and polymyositis.
Most patients are middle aged females. Characteristic feature is a speckled ANA
pattern.
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