Systemic lupus erythematosus (SLE) is an autoimmune illness that causes a characteristic butterfly-shaped rash on the face accompanied by inflammation of connective tissue, particularly joints, throughout the body. In autoimmune diseases, the immune system attacks the body instead of protecting it. Kidney, lung, and vascular damage are potential problems resulting from SLE.

The cause of SLE is unknown, though 90% of cases occur in women of childbearing age. A few drugs, such as procainamide, hydralazine, methyldopa, and chlorpromazine, may create SLE-like symptoms. Environmental pollution and industrial emissions were associated with an increased risk of SLE in one study.¹ In one reported case, zinc supplementation appears to have aggravated drug-induced SLE.² Ultraviolet radiation from sun exposure is a commonly recognised trigger of the skin manifestations of lupus.³ Some environmental chemicals such as hydrazine⁴ and food dyes such as tartrazine⁵ may be environmental triggers of SLE in susceptible people.

Risk factors include a family history of SLE, other collagen diseases or asthma,⁶ menstrual irregularity,⁷ beginning menstruation at age 15 or later,⁸ exposure to toxic chemicals,⁹ and low blood levels of antioxidant nutrients, such as vitamin A and vitamin E, or beta-carotene.¹⁰ Free radicals are thought to promote SLE.¹¹

Discoid lupus erythematosus (DLE) is a milder form of lupus that affects the skin. Like SLE, it’s not known what causes DLE, though sun exposure may trigger the first outbreak. DLE is most common among women in their thirties.