We describe a patient who experienced systemic adverse effects after the injection of botulinum toxin type B (Myobloc) to treat palmar hyperhidrosis. The adverse effects included blurry vision, indigestion, and a severe dry throat associated with dysphagia. Although systemic adverse effects have been described in the medical literature after the use of botulinum toxin type B for the treatment of cervical dystonia, to our knowledge, it has never been described as being associated with the treatment of palmar hyperhidrosis.

Hyperhidrosis is a troublesome problem that results in awkward social situations for those affected. Unfortunately, topical and oral medications, iontophoresis, and surgery have not proven to be efficacious in most patients. Because the eccrine glands are innervated by sympathetic nerves that use acetylcholine as the neurotransmitter, botulinum toxin is effective in temporarily reducing or abolishing sweat production. There have been no studies published to date on the effects or adverse effects of botulinum toxin type B on hyperhidrosis¹ but preliminary trials are under way.