Medical Health Encyclopedia

A number of conditions may resemble SLE:

• Scleroderma: Hardening of the skin caused by overproduction of collagen
• Multiple sclerosis: Fatigue, heaviness or clumsiness in the arms and legs
• Rheumatoid arthritis: Inflammation of the lining of the joints
• Sjögren's syndrome: Characterized by dry eyes and dry mouth
• Mixed connective tissue disorder: Similar to SLE, but milder
• Myositis: Inflammation and degeneration of muscle tissues
• Fibromyalgia: Chronic muscle pain
• Rosacea: Flushed face with pus-filled blisters
• Seborrheic dermatitis: Sores on lips and nose
• Lichen planus: Swollen rash that itches, typically on scalp, arms, legs, or in the mouth
• Leukoplakia: White spots on tongue or cheek
• Dermatomyositis: Bluish-red skin eruptions on face and upper body
• Lyme Disease: Bulls-eye rash, joint inflammation, and flu-like symptoms

Lyme disease is an acute inflammatory disease that is caused by the bacterium Borrelia burgdorferi. The bacteria is transmitted by the bite of a deer tick. Symptoms may go away in 3 to 4 weeks even without treatment, but other diseases may develop if the initial infection is not treated.

Click the icon to see an image of dermatomyositis.

Tests for Autoantibodies

Methods for measuring the antibodies involved with SLE vary and the range of results can be bewildering. Repeat tests may be needed.

Antinuclear Antibodies (ANAs). A primary test for SLE checks for antinuclear antibodies (ANA), which attack the cell nucleus.

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High levels of ANA are found in more than 98% of patients with SLE. A number of other conditions, however, also cause high levels of ANA, so a positive test is not a definite diagnosis for SLE:

• Antinuclear antibodies may be strongly present in other autoimmune diseases (such as scleroderma, Sjögren's syndrome, or rheumatoid arthritis).
• They also may be weakly present in about 20 - 40% of healthy women.
• Some drugs can also produce positive antibody tests, including hydralazine, procainamide, isoniazid, and chlorpromazine.