Cutaneous lesions of LE can be reproduced experimentally with both UVA and UVB light. While UVB is mainly responsible for causing skin cancer and lupus, UVA also may play a role. UVA can contribute to skin cancer, premature aging and is largely responsible for drug-induced photosensitivity. Both UVB and UVA can produce tanning. Exactly how UV light aggravates lupus is unknown.
Research suggests it alters DNA and protein in the skin.
The altered DNA may act as an antigen that triggers the autoantibodies and provokes an autoimmune response in the skin. The skin reacts to these substances, becomes red, inflamed and develops a rash. Photosensitivity reactions can also affect the internal organs. There, they may cause inflammation in organs and lead to systemic symptoms. Injury to people with LE in the workplace can be a cause for worker's compensation and litigation.