Risk Factors
The number of people diagnosed with lupus has more than tripled over the past four decades. This may simply indicate a greater degree of doctor training in recognizing the syndrome.
Gender
About 90% of lupus patients are women, most diagnosed when they are in their childbearing ages. Hormones may be an explanation. After menopause, women are only 2.5 times as likely as men to contract SLE. Flares 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 brother or sister 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.
Presence of Other Autoimmune Disorders
Rheumatoid Arthritis. Studies have investigated the relationship among hormones, SLE, and rheumatoid arthritis, another autoimmune disease. Higher levels of estrogen are associated with SLE, while lower levels are associated with rheumatoid arthritis. Some research suggests 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 that initially attacks the lining, or synovium, of the joints.
Drug-Induced Lupus
Many prescription drugs can cause lupus-like skin symptoms. These include high blood pressure (hypertension) medications, including hydrochlorothiazide, angiotensin-converting-enzyme inhibitors, and calcium-channel blockers. About 40 different drugs have been linked to lupus onset. Anyone diagnosed with cutaneous lupus erythematosus should be sure to tell their doctors all the medications (including herbs and supplements) that they are taking.
Lifestyle Factors
Smoking. Smoking may be a risk factor for triggering SLE and can increase the risk for skin and kidney problems in women who have the disease.
Possible SLE Triggers
In genetically susceptible people, there are various external factors that can provoke an immune response. Possible SLE triggers include colds, fatigue, stress, chemicals, sunlight, and certain drugs.
Viruses. Patients with SLE may be more likely to have been exposed to certain viruses than the general population. These viruses include the Epstein-Barr virus (the cause of mononucleosis), cytomegalovirus, and parvovirus-B1. In particular, some research suggests a strong association between Epstein-Barr virus (EBV) and increased risk of lupus, particularly for African-Americans.
