Botulinum toxin type A is a safe and effective treatment for axillary hyperhidrosis over 16 months - A prospective study

Objective: To evaluate the safety and efficacy of botulinum toxin type A (BTX-A) (BOTOX) over 16 months in the treatment of bilateral primary axillary hyperhidrosis. Design: A 16-month study with initial double-blind randomization to 50 U of BTX-A or placebo per axilla. After 4 months, participants could receive up to 3 further treatments with open-label BTX-A over 12 months. Setting: Fourteen dermatology or neurology clinics in Germany, Belgium, and the United Kingdom. Participants: Of 207 individuals aged between 17 and 74 years who had persistent bilateral primary axillary hyperhidrosis that interfered with daily activities, 174 (84%) completed the study. The baseline gravimetric assessment was a spontaneous sweat production of 50 mg or greater in each axilla prior to initial treatment. Main Outcome Measures: At week 4 after each treatment, the response rate of subjects who had at least a 50% reduction from baseline in axillary sweating, as measured by gravimetric assessment, was evaluated. Ad-verse events were spontaneously reported throughout the study, together with quality-of-life parameters and assessment of neutralizing antibodies to BTX-A. Results: Over the 16-month period, 356 BTX-A treatments were given to 207 subjects. After placebo treatment, the response rate at week 4 was 34.7%. After the first, second, and third treatment with BTX-A, response rates at week 4 were 96.1%, 91.1%, and 83.3%, respectively. For subjects receiving more than 1 treatment, the mean duration between BTX-A treatments was approximately 7 months; however, 28% of subjects completed the study after only I BTX-A treatment. Subjects' satisfaction after treatments was consistently high, their quality of life improved, and there was a reduction in the impact of the disease on their lives. The safety profile of BTX-A after repeated treatments was excellent and no confirmed positive results for neutralizing antibodies to BTX-A occurred. Conclusion: Repeated intradermal injections of BTX-A over 16 months for treatment of primary axillary hyperhidrosis is safe and efficacious.