Low-Dose Efficacy of Botulinum Toxin A for Axillary Hyperhidrosis

Abstract

Primary axillary hyperhidrosis is an autonomic neuronal dysfunction that can result in uncontrollable, excessive sweating.¹ Patients suffer from skin maceration, secondary microbial infections, drenching and ruining of clothes, and social stigmatization.² Botulinum toxin A blocks the autonomic innervation of sweat glands and has therefore become a preferred treatment modality for severe axillary hyperhidrosis that is unresponsive to other established therapies, eg, topical application of aluminum chloride.³ Several double-blind, placebo-controlled, multicenter clinical trials have shown that botulinum toxin A is a safe and highly effective therapy with high patient satisfaction.^3-7 However, most patients require more than 1 treatment over time, as sweating tends to recur after an average of 4 to 9 months. Also, botulinum toxin A treatments are more costly than topical applications of aluminum chloride and have to be administered intracutaneously, with precise placement and dosing of the drug. Thus, the necessity for optimizing botulinum toxin A treatment is evident. One approach to reduce treatment frequencies has been high-dose therapy.^8,9 However, high-dose therapy has been criticized as potentially risking antibody induction against botulinum toxin A.¹⁰ So far, no controlled trials have been conducted to prove the hypothesis that high doses are truly more effective than lower doses.^10,11