Systemic Lupus Erythematosus

Description

Alternative Names

Risk Factors

An estimated 500,000 Americans have been diagnosed with systemic lupus erythematosus, although surveys indicate that the prevalence may be much higher. The incidence of the disease has more than tripled over the past four decades. Some experts believe this may simply indicate a greater degree of physician training in recognizing the syndrome.

Gender

About 90% of lupus patients are women, most of whom are diagnosed when they are in their childbearing ages, a fact that might be explained by hormones. After menopause, women are only two and a half times as likely as men to contract SLE. Flare also become somewhat less common after menopause in women who have chronic SLE.

Ethnicity

African-Americans are three to four times more likely to develop the disease than Caucasians and to have severe complications. Hispanics and Asians are also more susceptible to the disease.

Family History

A family history plays a strong role in SLE; a sibling of a patient with the disorder has 20 times the risk as someone without an immediate family member with SLE.

Risk Factors in Children

The disease is rare in childhood. When it does occur, it is often associated with thrombotic thrombocytopenia purpura, a condition resulting from abnormally low levels of blood platelets. SLE in children may also be caused by certain medications, including minocycline and zafirlukast.

The Presence of Other Autoimmune Disorders

Rheumatoid Arthritis. One 1999 study investigated the relationship between hormones, SLE, and rheumatoid arthritis, another autoimmune disease. Higher levels of estrogen are associated with SLE, while lower levels are associated with rheumatoid arthritis. The study found that some patients, in fact, progress from one disease to the other, and that such transitions occur during major hormonal shifts, such as the onset of menopause or pregnancy.

Rheumatoid arthritis is a systemic autoimmune disease which initially attacks the synovium, a connective tissue membrane that lines the cavity between joints and secretes a lubricating fluid.

Fibromyalgia. Fibromyalgia, which some experts believe may be another autoimmune disorder, is also a common co-condition in SLE patients.

Click the icon to see an image of fibromyalgia.

Drug-Induced Lupus

Many prescription agents can cause lupus-like skin symptoms. In one study, the most common drugs causing these symptoms were hypertension medications, including hydrochlorothiazide, angiotensin-converting-enzyme inhibitors, and calcium-channel blockers. However, about 40 drugs in current use have been linked with the onset of lupus. Anyone diagnosed with cutaneous lupus erythematosus should be sure to tell their physicians all the medications (including herbs and supplements) that they are taking.

Factors Associated with SLE

Smoking. One study reported that smokers are almost seven times more likely to develop SLE than nonsmokers, and ex-smokers have a 3.6-fold risk, according to research published in 2001.

School Teaching. One interesting study reported a higher risk for autoimmune diseases in schoolteachers, possibly because of high exposure to infectious agents, such as Epstein-Barr virus (the cause of mononucleosis), which have been associated with a higher risk for these diseases.