Photodynamic inactivation of verrucae vulgares. I.

Verrucae vulgares (v.v.) stained in vivo and in vitro with 0.1% and 1% proflavine in 100% dimethylsulphoxide (DMSO) and 0.1% and 1% neutral red in 100% DMSO were examined grossly and by fluorescence microscopy. Light transmission studies were made using both whole v.v. embedded in methacrylate and 5 micrometer frozen sections. The dyes were seen to penetrate to the epidermal and dermal structures in the in vivo stained v.v. and accumulate in the cell nuclei. The average concentration of neutral red in the v.v. was estimated to be 2 X 10(-5) M. The concentration of proflavine was lower than that, but exceeded 10(-6)M. There was diffuse staining throughout the in vitro stained warts. From 400-600 nm the warts were penetrated by at least 1% of the light directed toward their surfaces.