A multi-center, cross-sectional questionnaire survey in Japan (KOBE study) exploring factors associated with primary focal hyperhidrosis

Background/aim: Primary focal hyperhidrosis (PFH) is defined as a condition characterized by excessive sweating in localized areas, which causes patients to experience difficulties in daily life, regardless of temperature or psychological stress. Previous surveys in Japan have revealed that the majority of patients with PFH may not visit medical institutions. Identifying the factors potentially associated with PFH is useful for detecting unmedicated patients and providing appropriate medical interventions. In this study, we explored factors associated with PFH in a multi-center, cross-sectional questionnaire survey (KOBE study). Methods: This study enrolled patients aged 5-64 years who visited 1 of the 24 dermatological institutions in Japan between April and July 2024 and completed a questionnaire (registered at the Japan Registry of Clinical Trials: jRCT1050250083). A combination of univariate and multivariate logistic regression analyses was performed to explore the associated factors. Results: A total of 3,617 participants were included in the analysis. The prevalence of PFH was 15.0% (544 of 3,617 participants). Among the potential associated factors, the odds ratios (ORs) were higher in order of axillary osmidrosis (OR = 5.440), psoriasis (OR = 1.830), wet earwax (OR = 1.780), a definite Hospital Anxiety and Depression Scale-Anxiety (HADS-A) score (OR = 1.780), a doubtful HADS-A score (OR = 1.460), and smoking (OR = 1.450). Receiver operating characteristic (ROC) curve analysis indicated that a HADS-A score of 6 was the optimal cutoff value for suspecting PFH. Conclusion: These findings may aid in detecting unmedicated potential patients in routine clinical practice and promoting active intervention for the disease, ultimately improving the quality of life and well-being of patients with PFH.