A single-blinded, placebo-controlled clinical trial evaluating the safety and efficacy of topical anesthesia with dichlorotetrafluoroethane prior to botulinum toxin type a injections for palmar hyperhidrosis

Abstract

Botulinum toxin type A is FDA-approved for treatment of strabismus, blepharospasm, cervical dystonia, and glabellar rhytides. This medication has also been used off-label for the treatment of localized hyperhidrosis. However, pain on injection, especially in the palmar area, may limit the use of this therapy. The use of dichlorotetrafluoroethane spray is easy and safe, and may significantly reduce injection pain. The primary objectives of this study are to evaluate the safety and efficacy of dichlorotetrafluoroethane spray when used as a topical anesthetic prior to Botulinum toxin type A injections and determine if its use affects the efficacy of Botulinum toxin type A in the treatment of palmar hyperhidrosis.Ten right-handed participants with clinically diagnosed palmar hyperhidrosis will be enrolled in this study. Participants will be asked to discontinue use of all treatments during a 2 week washout period. On Day 0, participants will receive injections on the palms and digits with 100U of Botulinum toxin type A per hand. Each hand will be randomized; immediately before each injection, one hand will be sprayed with dichlorotetrafluoroethane spray and the other hand will be sprayed with a pressurized air can (placebo). Pain will be measured using a Visual Analog Scale (VAS) 1 minute and 30 minutes after injection. A phone visit will be conducted at Day 7 for assessment of adverse events and quality of life. Study evaluations take place on Day 30, Day 60, Day 90, Day 120, and at 30-day intervals until participants return to baseline sweating levels. At each of these visits, dynamometer (grip strength) and gravimetric (sweat levels) measurements will be taken, an iodine starch test will be performed, photographs will be taken, and participants will complete quality of life and hyperhidrosis severity assessments. Participants will be contacted via telephone 30 and 90 days after their exit visit in order to assess quality of life at these time points. At the end of the study, an independent dermatologist will review the photographs to evaluate changes in the iodine starch test.The study is ongoing and final results and conclusions will be presented. Botulinum toxin type A is FDA-approved for treatment of strabismus, blepharospasm, cervical dystonia, and glabellar rhytides. This medication has also been used off-label for the treatment of localized hyperhidrosis. However, pain on injection, especially in the palmar area, may limit the use of this therapy. The use of dichlorotetrafluoroethane spray is easy and safe, and may significantly reduce injection pain. The primary objectives of this study are to evaluate the safety and efficacy of dichlorotetrafluoroethane spray when used as a topical anesthetic prior to Botulinum toxin type A injections and determine if its use affects the efficacy of Botulinum toxin type A in the treatment of palmar hyperhidrosis. Ten right-handed participants with clinically diagnosed palmar hyperhidrosis will be enrolled in this study. Participants will be asked to discontinue use of all treatments during a 2 week washout period. On Day 0, participants will receive injections on the palms and digits with 100U of Botulinum toxin type A per hand. Each hand will be randomized; immediately before each injection, one hand will be sprayed with dichlorotetrafluoroethane spray and the other hand will be sprayed with a pressurized air can (placebo). Pain will be measured using a Visual Analog Scale (VAS) 1 minute and 30 minutes after injection. A phone visit will be conducted at Day 7 for assessment of adverse events and quality of life. Study evaluations take place on Day 30, Day 60, Day 90, Day 120, and at 30-day intervals until participants return to baseline sweating levels. At each of these visits, dynamometer (grip strength) and gravimetric (sweat levels) measurements will be taken, an iodine starch test will be performed, photographs will be taken, and participants will complete quality of life and hyperhidrosis severity assessments. Participants will be contacted via telephone 30 and 90 days after their exit visit in order to assess quality of life at these time points. At the end of the study, an independent dermatologist will review the photographs to evaluate changes in the iodine starch test. The study is ongoing and final results and conclusions will be presented.