Dilution of botulinum toxin A in lidocaine vs. in normal saline for the treatment of primary axillary hyperhidrosis: a double‐blind, randomized, comparative preliminary study

Background  Botulinum toxin A (BTX‐A) is an effective and safe treatment modality for primary axillary hyperhidrosis. However, some patients experience considerable pain during injections. Design  Dilution of botulinum toxin A in lidocaine vs. in normal saline for the treatment of primary axillary hyperhidrosis: a double‐blind, randomized, comparative preliminary study. Objective  The aim of this study was to compare the efficacy, safety and pain tolerance of lidocaine‐diluted BTX‐A vs. saline‐diluted BTX‐A for the treatment of axillary hyperhidrosis. Methods  Eight patients were injected with 50 U of BTX‐A diluted in 0.5 mL of saline and 1 mL of 2% lidocaine into one axilla and 50 U of BTX‐A diluted in 1.5 mL of saline into the other axilla in a randomized fashion. The pain associated with the injections were self‐assessed by the subjects using a 100‐mm visual analogue scale (VAS). Results  Lidocaine‐diluted BTX‐A and saline‐diluted BTX‐A were similarly effective regarding the reduction in sweat production, the onset of sweat cessation and the duration of hypo/anhidrosis. Nevertheless, the pain VAS score during the injections was significantly lower in the axilla treated with lidocaine‐diluted BTX‐A than the one treated with saline‐diluted toxin. Limitations  Preliminary study due to relatively small sample size. Conclusion  Botulinum toxin A diluted in lidocaine causes significantly less pain than BTX‐A diluted in saline, whereas it is is equally effective and safe as the latter one in treating axillary hyperhidrosis. Therefore, we suggest that lidocaine‐diluted BTX‐A may be a better treatment option for the patients with primary axillary hyperhidrosis.