The pathogenesis of acne is not clear, although we now have more information about it. Much has been written and said about the role of the endocrines, although the exact influences of their products and activity and relationships to one another remain to be spelled out. The anatomical and histogenic factors in acne have lately received much attention. By these approaches certain changes are commonly seen and are suspect. One of these is the keratinous ring at the follicular ostium. It seems, however, the latter is by no means an obligatory preliminary to the appearance of the overt acne lesion. Diet has received its full share of consideration and speculation. Most dermatologists agree that such foods as chocolate and nuts, and the 2 halogen radicals, iodides and bromides, exacerbate acne. There is disagreement about the effect of fats and lipids; however, many physicians have limited sugar in the acne diet.