Frontal Alopecia after Repeated Botulinum Toxin Type A Injections for Forehead Wrinkles: An Underestimated Entity?

[BACKGROUND] Injections of botulinum toxin type A in the forehead have never been reported to cause hair side effects.

[OBJECTIVE] The aim of this paper is to report a new type of alopecia, which we have seen in women undergoing periodic injections of botulinum toxin type A for forehead wrinkles, and to differentiate it from other types of hair loss.

[METHODS] We conducted an observational study on 5 females recruited from a private and an institutional practice who complained of progressive recession of the hairline after periodic injections of botulinum toxin type A in the forehead.

[RESULTS] Alopecia of the frontal hairline was evident in all 5 patients, with absence of skin atrophy or scarring and progressive hair miniaturization at trichoscopy.

[CONCLUSION] Dermatologists should be aware of the possible occurrence of frontal alopecia after repeated injections of botulinum toxin type A for forehead wrinkles.