Primary hyperhidrosis prevalence and characteristics among medical students in Rio de Janeiro.

Background: Hyperhidrosis is a pathological condition defined by excessive sweating beyond thermoregulatory physiological needs, which can cause substantial psychological impact and impairment of daily activities. Studies regarding its prevalence, however, are scarce and vary widely in their findings. The population of medical students is a particularly interesting subset for its recurring demand of physical contact during patient examination or procedures, and the potential for professional adversity. We aimed at furthering the comprehension of this disease prevalence and characteristics among medical students.

Methods: Questionnaires inquiring about the presence and characteristics of Primary Hyperhidrosis (PH) were applied through either written or digital means to all eligible medical students enrolled in three Medical Schools in the State of Rio de Janeiro who agreed to take part in the study. Demographic data regarding gender, ethnicity, current age, weight and height was collected in addition to clinical data (sweat site, age of onset, familial history, severity and previous treatments). Severity was evaluated through the Hyperhidrosis Disease Severity Scale (HDSS) and a symptoms survey.

Findings: Our response rate was roughly 1/3 of all eligible students (900/2700). PH prevalence was 20.56% (185/900). It was similar between men and women (23.08% and 19.41%, respectively) and strongly associated with family history of the disease (Prevalence Ratio of 4.27). Regarding ethnicity, of the total sample 73.78% (664/900) self-declared white, among which 19.28% (128/664) had PH. Mixed-race and other ethnicities encompassed 26.22% (236/900) of the sample, among which 24.15% (57/236) had PH. Most positive subjects (64.32%) presented associated forms of PH. Overall involvement of each site (both associated and isolated) was: 63.78% axillary, 50.81% palmar, 43.24% plantar, 20.54% craniofacial, 18.38% facial flushing and 2.16% gustatory sweating. Mean current age was 23.11(±4.04) years for PH patients, and age of onset was ≤18 years in 93.94% of cases. Regarding body mass index (BMI), 71.09% of PH patients had BMI<25kg/m2 and only 4.69% presented BMI≥30kg/m2, none ≥35kg/m2. Some degree of life quality impairment was reported by 89.20% of PH patients, and 23.89% had HDSS 3 or 4 (moderate to severe).

Conclusions: PH prevalence among Rio de Janeiro medical students was 20.56%, similar between men and women, predominating associated presentations, axillary, palmar and plantar sites, strong familial history, age of onset before 18 years, and some degree of life impairment.