The Level of Efficacy and the Long-Lasting Effect of Iontophoresis of Botulinum Toxin Type A on Primary Hyperhidrosis (pHH) of Hand

Primary hyperhidrosis (PHH), is an idiopathic disorder, characterized by excessive uncontrollable sweating in the hands, armpits, groin, feet and face. Various methods such as injection of Botulinum Toxin Type A (BTX-A) which is associated with severe pain during injection and also muscle weakness for hyperhidrosis treatment have been suggested. Delivering the BTX-A via iontophoresis is shown to be a noninvasive treatment with the minimum side effects. The aim of this study was to investigate the level of efficacy and persistency of iontophoresis of BTX-A on the patients with palmar PHH. In this semi-experimental study eight patients which were suffering from palmar PHH (aged 19-26 years) were treated with iontophoresis of BTX-A on patient’s dominant hand and the other hand was treated with iontophoresis of normal saline as control. Gravimetric and iodine-starch tests were performed to evaluate sweating quantity and muscle strength was assessed by grip and thumb-index pinch tests. Treatment evaluation sessions were at baseline and at 2 and 4 days and also 1, 2, 3, 4, 8, and 12 weeks after treatment. Our results showed that, the mean of sweating rate on dominant hand was significantly reduced at 1 week (p=0.03), 3 weeks (0.01), 1 month (p=0.02), 2 months (p=0.03) and 3 months (p=0.02) post treatment and on control (nondominant) hand 3 weeks (p=0.02) and one month later (p=0.04) after the treatment. There was also reduction in sweating at the other sessions but was not significant. The muscle weakness was not observed in none of the investigated patients. The results suggest that iontophoresis of BTX-A can induces significant reduction in hand sweating rate which was lasted for 3 months and in contrary to the injection method had no pain or side effects such as muscle weakness.