A double blind study was made on a group of 35 children, 8 of whom were allergic to Grass and 27 allergic to Pteronyssinus and Farinae Dermatophagoides. We verified the efficacy and tolerability of a new immunotherapy called E.P.D. (Enzyme Potentiated Desensitization). This particular immunotherapy consists in an intradermal injection of a mix made up of an allergic solution at extremely low doses and an enzyme, beta-glucuronidase. The vaccine is administered once a year, two weeks before pollen peaks for children with seasonal allergies and two times a year, in February and November, for children with non-seasonal allergies (Dermatophagoides). The results, statistically analyzed on the basis of a symptoms score, showed good clinical efficacy in patients affected by both seasonal and non-seasonal allergies. Due to the clinical effectiveness, easy administration and excellent tolerability of the immunotherapy, E.P.D. is particularly suited for treating or reducing allergic symptoms in allergic children.