ABSTRACT
BACKGROUND: There is a paucity of data on the prevalence of multifocal primary hyperhidrosis and changes in hyperhidrosis severity over time. OBJECTIVE: The goal of this study was to better understand multifocal primary hyperhidrosis, prevalence and distribution of hyperhidrosis by focal site, age of onset of symptoms by focal area, and change in hyperhidrosis severity over time and with seasons. MATERIALS AND METHODS: The International Hyperhidrosis Society, through an unrestricted research grant from Revance Therapeutics, conducted an online survey of registered visitors to its Web site. Participants identified as having "excessive sweating" and opted to participate in the survey (23 questions) after an e-mail invitation. RESULTS: The survey data illustrate that multifocal primary hyperhidrosis is more common than previously believed and that multifocal hyperhidrosis is more common than singular focal hyperhidrosis (81% of patients reported 3 or more focal hyperhidrotic sites). The data also show that sweating symptom severity does not improve with age but stays the same or gets worse and is "bothersome" throughout the year. CONCLUSION: Recognition of the chronic and multifocal nature of primary hyperhidrosis is useful for treating hyperhidrosis patients long term and illustrates a need for treatments or treatment combinations that are effective for multiple body areas.