Until recently there were few data available on the prevalence of primary hyperhidrosis. Many articles on hyperhidrosis quote a pilot epidemiology study reported by Adar and colleagues in 1976 that found an incidence of 0.6% to 1.0% in a young Israeli population. Recently a consumer survey of a nationally representative sample of 150,000 households in the U.S. screened for the presence of hyperhidrosis. The survey results showed that the prevalence of hyperhidrosis in the U.S. is 2.8% (7.8 million Americans). Of those with hyperhidrosis, only 38% consulted their physician about their excessive sweating. The authors of the survey report conclude that hyperhidrosis actually affects more people than previously thought.
Several series of patients treated by endoscopic thoracic sympathectomy (ETS) report a family history in 35% and 56%, respectively.[35,82] A study of the familial aggregation of hyperhidrosis also suggests that the disorder may be more common than previously thought. When family history was analyzed in a group of patients with primary hyperhidrosis, 65% of patients reported a family history compared to no family history in controls. On the basis of these findings, the disease allele is present in 5% of the population, with an observed penetrance of 25%. Ro and colleagues conclude that because many of those with hyperhidrosis are reluctant to seek treatment, the previously reported incidence may be “a gross underestimation.”
Focal primary hyperhidrosis usually has an onset during childhood or adolescence. In a series of Taiwanese patients with palmar hyperhidrosis, 75% had childhood onset, with the remainder presenting during puberty. In a study of 850 patients with palmar, axillary, or facial hyperhidrosis, 62% said they had the symptoms “…as long as they could remember,” 33% said the onset occurred during puberty, and 5% reported their first symptoms as adults. Hölzle from Germany states that primary hyperhidrosis starts in puberty, peaks in the third and fourth decade, but can be seen in childhood and even infancy. In the U.S. consumer survey, the average age at onset was 25 years, but varied with location of hyperhidrosis. The average age of onset for those with palmar or axillary symptoms and symptoms in one other location was 22 years, for those with axillary alone age of onset was 19 years, and for those with palmar alone age of onset was 13 years. The highest prevalence rates were seen between 25 and 65 years of age (3.5% to 4.5%), and the lowest under 12 years of age (0.5% to 0.7%) prevalence. In this survey, there were no gender differences in prevalence.
Prevalence of the types of primary hyperhidrosis based on body location has been reported in several patient populations. In 256 German patients reported by Hölzle, 115 had excessive sweating in the axillae, 86 on the palms, and 75 on the soles. In a series of 382 French patients treated with ETS, 30% had palmar and plantar hyperhidrosis, 51% had palmoplantar and axillary hyperhidrosis, 6% had palmoplantar and facial hyperhidrosis, 5% had all areas involved, and 8% had axillary hyperhidrosis only. According to the U.S. consumer survey, 51% of hyperhidrosis patients have axillary hyperhidrosis alone or in combination with hyperhidrosis in another location, 9.5% have axillary hyperhidrosis alone, 25% have palmar hyperhidrosis alone or in combination with hyperhidrosis in another area, and only 1% have palmar hyperhidrosis alone.