Long-Term Quantitative Benefits of Botulinum Toxin Type A in the Treatment of Axillary Hyperhidrosis

BACKGROUND: Although axillary hyperhidrosis is readily treated with botulinum toxin, the time course of benefits is not well established. OBJECTIVE: To quantify the long-term effectiveness of botulinum toxin type A (BTX-A) for the treatment of axillary hyperhidrosis. METHODS: This was a double-blind, placebo-controlled study. Eighteen patients received intradermal injections of either 100 U BTX-A (50 U/ml/axilla) or placebo. Sweating per surface area was quantified monthly for 5 months. RESULTS: The BTX-A group had an average reduction in sweat production of 91.6% at 2 weeks (from 5.03 ml/min/m(2) to 0.42 ml/min/m(2), P <.05). The average reduction over 5 months was 88.2%. At the end of the study, only 1 of 12 BTX-A-treated patients had returned to baseline sweat production. CONCLUSION: These quantitative results demonstrate that BTX-A is a safe and effective treatment for axillary hyperhidrosis and that the benefits last for at least 5 months.