ON THE MECHANISM OF PHOTOSENSITIZATION IN MAN

Abstract

Three types of response were elicited and differentiated in hu-man skin: (A) Normal erythema and pigmentation produced by radiation of wave lengths less than 3200 A; this is independent of O2. (B) Urticaria solare, a pathological "triple response" elicited by wave lengths 4000-5000 A: this is independent of O2 and not followed by pigmentation. (C) Photodynamic "triple response" following intradermal injection of "photodynamic" dyes and irradiation with wave lengths absorbed by the dye; this is dependent upon the presence of O2, and is followed by pigmentation.