This article is structured around a literature review that was carried out using Ovid and Medline with the key words "botulinum," "toxin," and "ENT." Botulinum toxin has been used safely in humans for more than 20 years. The effects are transient, such that treatments are required to be repeated at intervals. Its application to ENT provides a useful tool to treat dystonia, autonomic dysfunction, facial nerve paresis, and hyperfunctional lines. It may also be of benefit in laryngeal rebalancing and the treatment of headaches. Further research is being carried out and new indications for treatment with botulinum toxin may include sialorrhea and rhinorrhea.

Introduction. This article reviews the mechanism of action of botulinum toxin and provides an overview of its use in hand disorders relevant to hand therapy such as hyperhidrosis, spasticity, dystonia, tremor, Parkinson's, obstetrical brachial plexus palsy, flexor tendon rehabilitation, lateral epicondylitis, Raynaud's and carpal tunnel syndrome. Methods. A narrative review of the literature retrieved through electronic databases using keywords botulinum toxin, hand, therapy, and reviewing the bibliographic references cited. Results. Sixty-five original articles and meta-analyses were reviewed. The number and quality of the published reports for each disorder are very variable but generally botulinum toxin is reported to be an effective adjunct to therapy in the treatment of a wide variety of hand and upper limb pathologies. Discussion. A surprising number of hand and upper limb conditions have been successively treated with botulinum toxin, but most require botulinum toxin to be used in conjunction with hand therapy to achieve more effective outcomes for longer duration. Neuromuscular disorders seem to be most responsive to botulinum toxin treatment. Therapists should be aware of the potential benefits of botulinum toxin injections for a wide range of hand disorders and when appropriate discuss these with patients and other health professionals. Conclusion. Botulinum toxin has an effective and growing role in hand therapy.