Many traumatic factors have been established as precipitating chronic discoid lupus erythematosus. Some of them are direct burns produced by substances such as hot fat, steam, radiant heat, and sunlight. Seven cases were reported to have followed mustard-gas dermatitis.1I here report a case of lupus erythematosus which developed from dermatitis produced by muriatic acid. This chemical substance, now known as hydrochloric acid, is used extensively in industry for cleansing and bleaching purposes. REPORT OF CASE E. R., a 42-yr.-old Negro who was engaged in the construction industry, was burnt with hydrochloric acid when he was working at the foot of a scaffold which held men who were cleaning the walls of a building. The details of the history are that on May 28, 1950, he accidentally looked up at the men above him and received splashes on his face and forehead of the solution they were using. A