The etiology of acne vulgaris is still obscure. Numerous factors, such as seborrhea, bacterial infection, disturbances of carbohydrate and fat metabolism and the ingestion of certain halogens and foods, have all been assumed to be of importance in individual cases. However, at the present time these are considered secondary, and there is still no adequate explanation for the causation of the disease. Acne is strikingly a disease of adolescence and has occasionally been associated clinically with disturbances of the endocrine system, especially of the gonads. Bloch,1in a study of over 4,000 school children, has shown a close correlation between the development of acne and the appearance of physical evidences of sexual development. His figures show acne to be most common in girls at the age of 17 and in boys at the age of 18. It is also well known that in women exacerbations of the eruption are