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.