Why is this disease called lupus?

The term lupus which means "wolf" in Latin has several supposed origins. This term was originally used to describe a skin condition that is reminiscent of wolf bites. It appears for the first time in the observation of the disease of the Bishop of Liège, Eraclius, reported by Herbert of Tours in 916 A.C. "He Eraclius, suffered from an ulcerative disease, lupus, which manifested itself by a red line on the forehead." The name lupus will be assigned to this erythematous (red) rash with ulcerations that cover different dermatological lesions, such as tuberculous lupus and lupus vulgaris. Another supposed origin is related to the shape in carnival wolf mask that would take the eruption of the face (vespertilio), emblematic of the disease.

The mechanisms that cause it are complex.