Topically applied botulinum toxin type A for the treatment of primary axillary hyperhidrosis: results of a randomized, blinded, vehicle-controlled study.

OBJECTIVE The objective was to demonstrate that botulinum toxin type A (BTX-A) can be delivered to targeted skin sites with topical application for the treatment of primary axillary hyperhidrosis. METHODS This randomized, blinded, vehicle-controlled study enrolled 12 patients with primary axillary hyperhidrosis with greater than 50 mg of sweat produced per 5 minutes. BTX-A (200 U), combined with a proprietary transport peptide molecule to bind the toxin in a noncovalent manner, was topically applied to one axilla; vehicle without BTX-A was applied to the other axilla. Rates of sweat production were measured and imaged at baseline and 4 weeks after application. RESULTS Two patients were excluded from analyses. At 4 weeks, 10 axillae treated topically with BTX-A demonstrated a 65.3+/-21.5% mean reduction in sweating relative to the same-patient, vehicle-control axillae, which had a 25.3+/-66.2% mean reduction. The 40% difference in mean sweat reduction between groups was statistically significant (p<.05). Quantitative image analysis of the results of the Minor's iodine starch test confirmed the reduction of sweat production in the BTX-A-treated versus the vehicle-treated axillae. CONCLUSION Topically applied BTX-A appears to be safe and may prove to be effective for the treatment of axillary hyperhidrosis.