Friction blister

Abstract: A longitudinal single-blind study was conducted to test the friction blister prevention properties of synthetic acrylic socks in a generic construction. This study serves as a comparison with the authors' previous work comparing acrylic and cotton socks in a patented padded construction. Twenty-seven long-distance runners provided data regarding dampness, temperature, friction blister incidence, severity, and size. Two different socks were tested; each was identical in every aspect of construction except the fiber content. One test sock was composed of 100% synthetic acrylic fibers, and the other was composed of 100% natural cotton fibers. These results were unsuccessful at demonstrating any superiority of cotton or acrylic fibers when knitting produced a generic "cushion sole" sock. The superiority of acrylic fibers has thus far been demonstrated only when sock knitting provides adequate anatomical padding [corrected].

Abstract: BACKGROUND: Friction blister research has focused on prevention and treatment approaches rather than exploring the pathophysiology of the friction blister. Increased skin hydration has been purported to be a key risk factor in friction blister development. This study aimed to test the effect of increased skin surface hydration on the risk of friction blister creation. METHODS: The skin on one foot was hydrated by soaking the foot in water. Intermittent loading was carried out until an observable change of 3°C was evident using infrared thermography. The contra lateral foot acted as a control. Skin hydration and elasticity was measured using electrical capacitance and negative pressure respectively. RESULTS: The rate of temperature change of the hydrated group was significantly greater than that of the non-hydrated foot group (P = 0.001) and showed a strong positive correlation (r = 0.520) with skin surface hydration. Weak negative correlations were seen between skin elasticity and rate of temperature change in response to load application (r = -0.166) and skin surface hydration and elasticity at baseline (r = -0.195). CONCLUSION: In controlled experimental conditions increased skin surface hydration increases the rate of temperature change of the skin in response to load application and consequently increases the risk of blister creation.

Abstract: In connection with studies on vitamin A transport to keratinocytes in vivo, the retinol, retinolbinding protein (RBP), and prealbumin contents of blister fluid obtained subepidermally (suction) or intraepidermally (friction) were analyzed. The median concentrations of the three components in suction blister fluid (SBF) were all about 33% of the serum concentrations. Corresponding values for α2-macroglobulin and total protein, measured as controls, were 27 and 30% respectively. The relative amounts of retinol and prealbumin in friction blister fluid (FBF) were the same as those in SBF. By contrast, FBF contained more RBP (median value 40%; P<0.01 vs SBF value). It is suggested that apo-RBP (RBP without retinol) is generated within the epidermis and contributes to the high RBP value in FBF. FBF constituents are probably derived from the intercellular space of the epidermis, at least during the initial phase of blister formation. Accordingly, RBP and prealbumin were identified in homogenates of pure epidermis. During the later stages of blister formation, FBF resembles an ultrafiltrate of dermal fluid, although different in this respect from SBF.