The possible dermatological and proctologic causes, of Pruritus Ani that often, due to its persistence and for its consequent lesions of scratching, becomes a real disease, are analysed. Particular attention is given to therapeutical treatment, describing which hygienic-dietetic rules must be followed and which treatments can be utilised, if the cause of the symptom is known and if it is possible to remove it or not. Moreover, personal experience on 312 patients examined in twelve years is reported.