Botulinumtoxin in the treatment of focal hyperhidrosis

Introduction: Botulinum A toxin (BTX-A) acts primarily at peripheral cholin ergic synapses, inhibiting the release of acetylcholine. Initially it has b een used to block the neuromuscular junction in focal dystonic and spastic syndromes. Recently there has been suggestions for potential clinical indic ations in non-muscular diseases where cholinergic terminals play a role. Gustatory sweating: In 1995 physicians reported a long-lasting anhidrotic e ffect of intracutaneous BTX-A injections in patients suffering from gustato ry sweating ((n)Frey's syndrome). Consequently, a number of clinical studie s demonstrated good efficacy of intradermal injections of botulinumtoxin in patients with focal hyperhidrosis. Focal hyperhidrosis of the palms and axillae: Focal hyperhidrosis is usuall y confined to the palms and axillae. Excessive sweating may be a social han dicap and an occupational hazard. The management of focal hyperhidrosis rem ains controversial. Topical antiperspirants are only effective in very mild cases. lontophoresis with tap water or anticholinergic drugs is messy and time consuming with only short-lived effect. Sympathectomy, the cornerstone of surgical management, is usually effective in palmar hyperhidrosis. Comp lications of this technique include surgical risks, postoperative and cosme tic problems and compensatory hyperhidrosis. Axillary hyperhidrosis: Several studies confirmed that intracutaneous injec tions of botulinum toxin are useful in the majority of patients with axilla ry hyperhidrosis resistant to conventional treatment. In axillary hyperhidr osis total doses are ranging from 200-400 mU Dysport((R)) or from 80 to 130 mU Botox((R)) to reach a good clinical response. Injections are usually we ll tolerated and no serious side-effects have been observed. The mean durat ion of anhidrotic effect ranges between 3 and 9 weeks. Palmar hyperhidrosis: The use of botulinumtoxin in patients with palmar hyp erhidrosis is rather difficult. The therapeutic window is smaller because i njections are complicated by transient weakness of the small hand-muscles. Furthermore the injections at the palms are painful which can be overcomed by application of local anaesthetics or the blockade of the ulnar and media n nerves. The duration of anhidrotic effect ranges from 20 to 50 weeks. Conclusion: Intracutaneous injections of botulinumtoxin should be offered t o patients with focal hyperhidrosis of the palms and axillae causing seriou s social, psychologic and occupational problems, resistant to other convent ional treatment options.