Clémence Berthin, Hervé Maillard
DOI: 10.2340/00015555-3307

Changes in the duration of efficacy of botulinum toxin A injections for primary axillary hyperhidrosis have not been studied in depth. The aim of this study was to assess such changes. In a retrospective cohort of 220 patients, seen over a 17-year period, duration of efficacy was recorded, including duration of efficacy of first and last injections. Of 220 patients, 117 fulfilled the study criteria (79 females and 38 males, age 17–79 years, mean age 38.3 years). Patients received 3–24 injections (mean 5.5). The duration of efficacy of the first injections was 3 weeks to 30 months (median 6 months), and the duration of efficacy of the final injections was 3 weeks to 66 months (median 8 months) (p < 0.001). An increase in duration of efficacy occurred in 62% of patients with repeated injections. Of the 20 patients with a follow up ≥10 years, the mean number of treatments was 8.25/patient; in 18 of these patients the duration of efficacy increased by > 50%. In conclusion, repeated botulinum toxin A injections lead to an increase in duration of efficacy without secondary decrease.

Hyperhidrosis consists of excessive sweating, which can negatively affect quality of life. Primary axillary hyperhidrosis is one of the most frequent causes of hyperhidrosis. Its treatment requires frequently repeated injections of botulinum toxin A (BTA). There are few published data on the repetition of BTA injections and its consequences. We report here a significant increase in the efficacy duration with the repetition of injections after more than 15 years of BTA treatment: 80% of patients reported a stable or increasing efficacy duration at the end of the follow-up, without side-effects.