Skin rash on a man's face. It is a symptom of the autoimmune disorder discoid lupus erythematosus (DLE). In this disorder, the immune system attacks connective tissue as if it were foreign tissue. DLE causes periodically-recurring inflammation and scarring in a defined area. Sunlight can start an attack, though the underlying cause is unknown and there is no cure. The symptoms can be treated with anti-inflammatory drugs.