What is bath PUVA?

The patient is immersed for 15 minutes in a bathtub containing five 10-mg capsules of methoxsalen dissolved in the water. Topical methoxsalen gradually loses its photoactivity, and the patient should ideally be treated with the standard UVA light treatments within 15 minutes after immersion. Bath PUVA therapy using trimethylpsoralen (TMP), which is more hydrophobic than 8-methoxypsoralen (8-MOP), has been used for more than 30 years in Sweden and Finland, with no observed increase in the number of skin cancers. It is also useful for patients who are not able to tolerate oral methoxsalen because of nausea, and for children under 15 years of age. This technique also may be adapted for use on the palms and soles for hand and foot dermatoses.

Coven TR, Murphy FP, Gilleaudeau P, et al: Trimethylpsoralen bath PUVA is a remittive treatment for psoriasis vulgaris. Evidence that epidermal immunocytes are direct therapeutic targets, Arch Dermatol 134:1263–1268, 1998.