Focal Hypertrichosis during Topical Tacrolimus Therapy for Vitiligo: A Case Report

We propose that the focal hypertrichosis was induced by tacrolimus. The hair growth-stimulating effects of tacrolimus have been established. It is reported that tacrolimus directly stimulates mouse whiskers in vitro and prolongs the anagen phase of hair growth when it is applied topically in mice. We believe that a greater awareness of this rare side effect of tacrolimus is warranted as tacrolimus is widely used in treating vitiligo.