Hypertrichosis of the malar areas and poliosis of the eyelashes caused by latanoprost.

The synthetic phenyl-substituted analog of prostaglandin F2 alpha (PGF2), latanoprost, is an intraocular pressurelowering drug for use in patients with primary open-angle glaucoma and ocular hypertension. Hypertrichosis of the eyelashes is a common reported adverse effect of this drug and of prostaglandin analogs in general since their introduction in the late 1990s.1 Here we present a case of poliosis and bilateral hypertrichosis of the malar vellus hairs that occurred during use of ophthalmic latanoprost solution for glaucoma treatment. A 64-year-old woman presented at our department complaining of excessive hair growth in both malar areas. The problem had started 6 months earlier and the hairs had progressively grown in number and diameter since then. Examination revealed hypertrichosis and poliosis of the eyelashes in addition to hypertrichosis of the malar areas. The whitened eyelashes were interspersed among normalappearing eyelashes in both eyes (Fig. 1). There were no signs of hypertrichosis on any other parts of the body. The patient had had bilateral glaucoma for 4 years, and had been using latanoprost eye drops since diagnosis. She had a history of hypertension and diabetes mellitus and had been taking amlodipine tablets and oral acarbose for the treatment of these diseases for about 8 years. She had no other cutaneous or systemic disorders and the results of routine biochemical and hormonal tests were within normal limits. She denied use of any topicals creams, including sunscreens or corticosteroids, on her face. Hypertrichosis is the growth of hair that is considered excessive for the age, sex, and race of an individual. It can occur all over the body or be isolated to small patches. PGF2analogs have been observed to promote hair growth and may have hypertrichotic effects. The mechanisms by which prostaglandins trigger hair growth, however, are not clear. It has been suggested that hypertrichosis of the eyelashes following administration of prostaglandin analogs for glaucoma treatment is probably a result of the induction of the anagen phase in telogen-phase eyelash follicles.2 These analogs may also prolong the anagen phase of eyelashes, leading to an increase in eyelash length.3 Eyelash hypertrichosis has been reported as a common adverse effect of ophthalmic latanoprost treatment, with frequency rates as high as 77%4 and 50.5%.5 Even brief exposure to an ophthalmic prostaglandin analog appears to be associated with eyelash changes. In one study, very brief exposure to latanoprost (<22 days) was reported to produce