Abstract
Friction blisters are common among outdoor enthusiasts, yet their causes remain uncertain. This study aimed to compare foot hydration in long-distance hikers with and without blisters, and to assess variability based on age and sex. An observational case-control study involving 86 hikers was conducted. Skin hydration was measured using a corneometer on various foot zones. Data on blister count, footwear, sex, age, and temperature were recorded. The most hydrated zones were the digital area, forefoot, and heel. Higher hydration was found in the blister group (61.6%) compared to the control group (38.4%). A significant relationship between hydration and blisters was observed in the left foot (p = 0.032). Total foot hydration was higher in women (p = 0.007) and inversely related to age (r = -0.333; p = 0.002). Hydration values above 30.40 a.u. in the right foot and 27.37 a.u. in the left foot were linked to blisters with 80% sensitivity. This study highlights the variability in foot hydration and its relationship with blisters. The influence of age and wet socks underscores the complexity of blister formation, emphasizing the need for future research on effective prevention.