Can the immersion time of PUVA bath therapy be shortened?

Up to now, there are only a few data available concerning the influence of bathing time on skin phototoxicity. We compared the erythemal responses of normal skin to bath PUVA with 8-methoxypsoralen (8-MOP) after 5, 10 and 20 min immersion time. Currently, 20 min is the routinely performed immersion time in many European countries, including Germany, while in other countries bathing times are shorter.