Seborrhea could also be the principal cause of the formation of dandruff. In fact it has been observed that Pityrosporum Ovale, which is held responsible for the formation of dandruff, and is normally present on the scalp, where it usually constitutes 40% of the microbic flora, reaches about 74% in seborrhea. This yeast is able, with its lipolytic enzymes, to liberate the fatty acids from the sebum and these, after oxidation has occurred, become very irritating. This irritation may stimulate the cells of the germinative stratum of the epidermis to increase their mycotic activity, thus causing greater formation of scales. The only confirmed finding however is that dandruff derives from an accelerated turnover of epidermic cells.