Lower relapse rate of botulinum toxin A therapy for axillary hyperhidrosis by dose increase

Primary focal hyperhidrosis is a common condition that gives rise to functional and emotional problems and may disturb professional and social life. Recently, low-dose intracutaneous injections of botulinum toxin A have been shown to induce a temporary anhidrosis, with relapses occurring usually after 4 to 6 months.

To evaluate the short- and long-term effectiveness and possible adverse effects of high-dose botulinum toxin therapy in the treatment of axillary hyperhidrosis.

In an open study, patients with focal hyperhidrosis were treated with intracutaneous injections of botulinum toxin A (Botox; Allergan Inc, Irvine, Calif). A total dose of 200 U of botulinum toxin A was used once per axilla. Patients were observed for up to 15 months.

University medical center.

Twenty-four patients with axillary hyperhidrosis were treated. Their ages ranged from 19 to 58 years (mean +/- SD, 34.8 +/- 12.4 years).

Reduction of sweating as assessed by the Minor iodine-starch test and planimetry of hyperhidrotic areas. Patients were interviewed at the end of follow-up about their satisfaction with this treatment.

Within 6 days, all patients reported cessation of excessive sweating. The mean +/- SD area of excessive sweating identified by the Minor iodine-starch test decreased from 19.27 +/- 11.95 cm2 to 0.25 +/- 0.61 cm2 (P<.001). The mean follow-up was 10.0 +/- 2.8 months (range, 5-15 months). Four patients (17%) reported a return of axillary hyperhidrosis after 7 to 10 months. All patients who experienced relapse showed an excellent response to a second treatment. The only adverse effects reported were temporary pain and burning during the injections. No muscular weakness, insensitivity, or systemic reactions were observed.

High-dose botulinum toxin A seems to be as safe as low-dose botulinum toxin A in the treatment of axillary hyperhidrosis. The preliminary data suggest a lower rate of relapse.