A preliminary study on topical cetirizine in the therapeutic management of androgenetic alopecia.

Androgenetic alopecia (AGA) is a common form of scalp hair loss that affects up to 50% of males between 18-40 years old. Several molecules are commonly used for the treatment of AGA, acting on different steps of its pathogenesis (Minoxidil, Finasteride, Serenoa repens) and show some side effects. In literature, on the basis of hypertrichosis observed in patients treated with analogues of prostaglandin PGF2α , was supposed that prostaglandins would have an important role in the hair growth: PGE and PGF2α play a positive role, while PGD2 a negative one. We carried out a pilot study to evaluate the efficacy of topical cetirizine versus placebo in patients with androgenetic alopecia. We found that the main effect of cetirizine was an increase of total hair density, terminal hair density and diameter variation from T0 to T1, while the vellus hair density shown an evident decrease. The use of a molecule as cetirizine, with no notable side effects, make possible a good compliance by patients. Our results have shown that topical cetirizine 1% is responsible for a significant improvement of the initial framework of androgenetic alopecia.