Non-cosmetic dermatological uses of botulinum neurotoxin.

Botulinum neurotoxin (BoNT) is renowned for its inhibitory effects on the neuromuscular junction. The evidence for its use in cosmetic dermatology and in non-dermatological indications is well established. We have systemically analysed the evidence for the non-cosmetic dermatological uses of BoNT. This review presents the many small studies showing promising results for the use of BoNT in a multitude of dermatological diseases, including (but not limited to) hyperhidrosis, Darier's disease, Hailey-Hailey disease, pompholyx and hidradenitis suppurativa. There is, however, the need for larger, double-blinded randomized control trials against established treatments to cement the evidence base underlying the use of BoNT in dermatology.