AUTHOR=Kosaka Keiji , Uchiyama Akihiko , Ishikawa Mai , Motegi Sei-Ichiro 
  
TITLE=The epidemiological and clinical association between primary focal hyperhidrosis and various skin disease in Japanese patients: outpatient questionnaire analysis
  
JOURNAL=Journal of Cutaneous Immunology and Allergy
  
VOLUME=Volume 9 - 2026
  
YEAR=2026
  
URL=https://www.frontierspartnerships.org/journals/journal-of-cutaneous-immunology-and-allergy/articles/10.3389/jcia.2026.15800
  
DOI=10.3389/jcia.2026.15800
  
ISSN=2574-4593
  
ABSTRACT=Hyperhidrosis, defined as excessive sweating beyond physiological needs. It impairs the quality of life (QOL) of patients. While there are many studies on the relationship between sweating and skin diseases, however few studies have been conducted from epidemiological perspective of hyperhidrosis on coexisting skin diseases. This study aimed to investigate the prevalence, severity, affected areas, and treatment history of hyperhidrosis among patients with skin diseases. An anonymous, self-report questionnaire was administered to 1,000 patients at the department of dermatology, Gunma University Hospital between June and August 2022, yielding 885 responses (88.5%). Hyperhidrosis was defined using the Hornberger’s diagnostic criteria, and severity was assessed by the Hyperhidrosis Disease Severity Scale (HDSS). The overall prevalence of hyperhidrosis among this skin disease patient cohort was 22.4% (n = 198), which was higher than the rate previously reported in Japan (10%–12.8%). Patients with hyperhidrosis were significantly younger (mean age 51.3 years) than those without (mean age 57.2 years; p < 0.01). Over half (54.3%) of affected patients reported severe or very severe symptoms (HDSS 3 or 4). The most common affected sites were the head/face (15.1%), followed by the axillary (8.7%). The prevalence was high in inflammatory skin diseases, with 29.2% of Atopic Dermatitis (AD) patients, 17.7% of psoriasis patients, and 7.1% of Alopecia Areata (AA) patients also having hyperhidrosis. Despite the high prevalence and severity, only a small fraction of hyperhidrosis patients (7.9%) reported a history of treatment. These findings suggest that hyperhidrosis is a common complication in skin disease. This high prevalence may be attributable to compensatory sweating caused by primary skin diseases. To improve patient’s QOL, dermatologists should actively screen for hyperhidrosis and combine sweat management with skin disease treatment.