To the Editor.— I was interested to read of the effect of 5-fluorouracil cream in the treatment of vitiligo as reported from Japan by Tsuji and Hamada. 1 They found that while fluorouracil alone had no effect, its use following epidermal abrasion resulted in repigmentation in the majority of patients. I wish to report the results of a pilot study of fluorouracil in dimethyl sulfoxide in vitiligo. 2 Dimethyl sulfoxide is known to enhance the penetration of many substances through the intact epidermis. Pretreatment with dimethyl sulfoxide has been reported to enhance the effect of fluorouracil in the treatment of solar keratoses. Thus, theoretically, dimethyl sulfoxide might allow the fluorouracil to induce repigmentation in vitiligo without epidermal abrasion. Eight adult patients with vitiligo for at least one year were recruited to the study with their informed consent. Three patients were white, and five Indian. The subjects applied 2.5% fluorouracil in