Open‐label pilot study to evaluate the effectiveness of topical bimatoprost on rhododendrol‐induced refractory leukoderma

Abstract

Rhododendrol (RD), 4‐(4‐hydroxyphenyl)‐2‐butanol, inhibits melanin synthesis and had been used in skin‐whitening cosmetic products until 2013. However, some individuals developed leukoderma on the skin where RD had been applied and have suffered from refractory depigmentation even after discontinuing RD application. Bimatoprost is a prostaglandin F2α analog and is often used for eyelash growth for cosmetic reasons as well as in the treatment of glaucoma. It was reported that bimatoprost induced skin pigmentation in addition to iris pigmentation as adverse effects. Therefore, we conducted an open‐label single‐center pilot study to evaluate the effectiveness of bimatoprost on refractory RD‐induced leukoderma. Eleven Japanese female patients with skin type III who developed leukoderma on the exact or slightly extended area of skin where RD had been applied and gained a halt of enlargement of leukoderma or repigmentation on a part of the affected skin after discontinuation of RD were enrolled. Bimatoprost 0.03% solution was applied on the leukoderma once daily for 3 months, and then the frequency of application was increased to twice daily for the subsequent 3 months. Ten patients completed the 6‐month course of bimatoprost application. In four patients, bimatoprost application brought slight improvement in RD‐induced refractory leukoderma by dermatologists’ evaluation. Because the number of enrolled patients was limited, further larger studies are necessary to better assess the effectiveness of bimatoprost in inducing repigmentation in patients with RD‐induced refractory leukoderma.

Long-term Use of Topical Bimatoprost on Rhododendrol-induced Refractory Leukoderma: A Case Report

“…However, it is difficult to draw a conclusion about the effectiveness of bimatoprost on RD-induced leukoderma based on a single case. As described previously (13), the area of skin affected was not measured, since the shape of the leukoderma was complex and it was on the neck of our patient. The surface of the leukoderma was uneven and difficult to measure.…”

“…The patient was enrolled in the previous pilot study to evaluate the effectiveness of bimatoprost on refractory RD-induced leukoderma in November 2016 at the age of 45 years (patient number RD-07), and applied bimatoprost on leukoderma on the left side of the neck once daily for 3 months, and then twice daily for another 3 months. The method is described in detail in the previous paper (13). The area of leukoderma on her neck, which was treated with bimatoprost, reduced in size significantly ( Fig.…”

“…Bimatoprost is a prostaglandin F2α analogue, which is often used to promote eyelash growth (5) for cosmetic reasons and in the treatment of glaucoma (6,7). Following reports that bimatoprost induces skin pigmentation as an adverse effect (8)(9)(10)(11)(12), we previously conducted an open-label single-centre pilot study to evaluate the effectiveness of bimatoprost on refractory RD-induced leukoderma (13). Following the previous study, in which patients applied bimatoprost for 6 months, one patient requested to continue application of bimatoprost.…”

Rhododendrol‐induced leukoderma update I: Clinical findings and treatment

“…Fukaya et al 14 was effective continued with a long-term application for another year and exhibited sustained improvement. 15 Additionally, a clinical study 16,17 demonstrated the benefits of topical prostaglandin derivatives in vitiligo.…”

“…Fukaya et al 14 reported the results of an open‐label pilot study investigating topical bimatoprost, a prostaglandin derivative, as a novel therapy. Reportedly, the application of 0.03% bimatoprost solution in patients with intractable RDL remaining on the neck or back of the hands, for 6 months resulted in a marginal improvement in four out of ten patients.…”