AXILLARY HYPERHIDROSIS

The use of BOTOX for the treatment of severe axillary hyperhidrosis was approved by the Food and Drug Administration in 2004 for patients whose hyperhidrosis is inadequately managed with topical agents.

Prior to administering BOTOX, many clinicians perform a Minor's starch iodine test to document the extent and severity of hyperhidrosis in each axilla. This can then be used to mark the skin with a grid of evenly spaced injection sites (Figure 37.1). The approved dose of BOTOX is 50 U per axilla, injected intradermally in 0.1- to 0.2-mL aliquots per injection site using a 30-gauge needle. In the pivotal trials, 100 U were diluted with 4.0 mL of nonpreserved saline. Discomfort with the axillary injections is minimal, and the placing of ice packs on the axillae prior to treatment generally provides sufficient anesthesia. Vibration and topical anesthetic creams have also been successfully employed to reduce pain.

The largest study reported to date was a fifty-two-week, multicenter, double-blind, randomized, placebo-controlled study involving 322 patients with axillary hyperhidrosis (Lowe et al. 2007). The proportion of treatment responders – those achieving a 2-point reduction on the Hyperhidrosis Disease Severity Scale (HDSS) – was significantly greater four weeks after treatment with BOTOX 75 U or BOTOX 50 U than after treatment with placebo (75% and 75% versus 25%; p < 0.001). The median duration of effect of BOTOX treatment was approximately six and a half months.