Botulinum toxin treatment of social anxiety disorder with hyperhidrosis: a placebo-controlled double-blind trial

Given the often prominent and persistent nature of hyperhidrosis in social anxiety disorder (SAD), to compare botulinum toxin type A to placebo for generalized SAD with hyperhidrosis, in combination with paroxetine.

Adults with severe axillary hyperhidrosis who met DSM-IV criteria for generalized SAD were randomly assigned to receive 1-time, bilateral, intradermal injections with either botulinum toxin type A or placebo (50 units/axilla). All subjects also received 8 weeks of open-label treatment with paroxetine. The primary outcome measure was the Hyperhidrosis Disease Severity Scale (HDSS). Secondary measures included the Hyperhidrosis Impact Questionnaire, Brief Social Phobia Scale, Liebowitz Social Anxiety Scale, Social Phobia Inventory, and Sheehan Disability Scale. Enrollment occurred from June 2002 to July 2004.

Forty subjects were randomly assigned to treatment and included in the analyses. Response rates were 75% (15/20) for botulinum toxin type A versus 15% (3/20) for placebo on the HDSS (p < .001). Botulinum toxin type A produced significantly more improvement in many daily activities that had been limited (p < .01), as well as greater improvement in work and social functioning and in overall disability (p < .05). Botulinum toxin type A was well tolerated, as was paroxetine.

Botulinum toxin is effective in reducing hyperhidrosis disability and limitations in everyday activities when given in association with paroxetine to subjects with SAD. While further assessment of botulinum toxin type A in SAD is recommended, including a trial of botulinum toxin type A monotherapy, the results suggest that this well-tolerated treatment deserves further consideration in overall management of SAD accompanied by hyperhidrosis.