Focal hyperhidrosis: effective treatment with intracutaneous botulinum toxin.

OBJECTIVE To evaluate the effect of intracutaneous injections of botulinum toxin type A on excessive focal hyperhidrosis. DESIGN Therapeutic before-and-after trial over 4 months. SETTING Neurological and dermatological university departments. PATIENTS Eleven patients with excessive axillary, palmar, or plantar hyperhidrosis fulfilling the following criteria: (1) local and systemic drug therapy had failed to improve their symptoms; (2) the patients were severely disabled with respect to their occupation and social activities; and (3) a successful treatment by botulinum toxin would obviate the need for destructive surgical procedures. INTERVENTIONS Three mouse units of botulinum toxin (Botox) per 4-cm2 skin area was injected intracutaneously in 16 axillae, 8 palms, and 2 soles. MAIN OUTCOME MEASURES Reduction of hyperhidrosis as documented by the Minor iodine-starch test and gravimetrical assessment of local spontaneous sweat production measured over 1 minute. RESULTS In all patients, botulinum toxin completely abolished sweating in the injected areas (P<.001) within 3 to 7 days. No relevant adverse effects occurred and no clinical recurrence of hyperhidrosis was observed within the follow-up period of up to 5 months. Occasionally, subclinical reactivation of sweat gland function was observed 4 months after treatment. CONCLUSIONS Intracutaneous botulinum toxin seems preferable to any hitherto used conservative or surgical procedures and may become the therapy of choice in pathological focal hyperhidrosis.