Related Experiment Video
Updated: Jul 11, 2026
Minimal Erythema Dose (MED) Testing
Published on: May 28, 2013
Phototesting in bath-PUVA: marked reduction of 8-methoxypsoralen (8-MOP) activity within one hour after an 8-MOP bath
C M Schempp1, E Schöpf, J C Simon
1Department of Dermatology, University Medical Center Freiburg, Germany.
Abstract:
It is not known how long after 8-MOP bath-PUVA administration erythema can be induced. Therefore, after determination of dose-dependence and kinetics of bath-PUVA erythema, we investigated the development of erythema using an erythematogenic UVA-dose (3 J/cm2) in time course experiments. Our results show that there is a loss of biological 8-MOP activity already 1 h after 8-MOP bath. This has important consequences for clinical practice with bath-PUVA, concerning the optimum time interval between the 8-MOP bath and irradiation as well as the persistence of photosensitivity in normal skin after bath-PUVA.
