VIEWPOINTCommentary on Viewpoint: Sweat electrolyte concentrations obtained from within occlusive coverings are falsely high because sweat itself leaches skin electrolytesLawrence E. ArmstrongLawrence E. ArmstrongPublished Online:01 Oct 2008https://doi.org/10.1152/japplphysiol.zdg-8179.vpcomm.2008MoreSectionsPDF (26 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat to the editor: All published comparisons of local sweat sampling techniques (e.g., filter paper, gauze, skin scraping, pipette, rubber glove, or arm bag collections) versus the whole body wash down method have reported that local samples contained higher electrolyte concentrations (4). The present paper by Weschler (5) provides a hypothetical mechanism for these findings [i.e., sweat leaches electrolytes from the stratum corneum (SC)] but does not consider a second testable and possibly concurrent mechanism. The following evidence supports absorption of water by the SC, increasing the tonicity of sweat irregardless of electrolyte leaching. 1) Skin swells when immersed in water for extended periods (4). 2) Hidromeiosis of eccrine glands, the progressive decrease of sweat rate, is proportional to skin wettedness and likely involves a mechanical obstruction of the sweat duct subsequent to SC swelling (3). Similarly, the skin disorder miliaria rubra (i.e., prickly heat) may involve SC swelling, closure of the sweat gland surface pore, bacterial infection, and inflammation (1). 3) Experimental evidence has shown that water diffuses into the SC, especially when air water vapor pressure is great or the skin is saturated with water; this diffusion increases in proportion to an increased sweat rate (2). 4) When sweat is collected in an impermeable arm bag, unrelated solutes (i.e., lactate, chloride, urea) concentrate in unison, as demonstrated by van Heyningen and Weiner (statistical r2 = 0.84 to 0.94; see Fig. 2 in Ref. 4). Indeed, these investigators recognized the absorption of water by the SC as a plausible explanation for their findings.REFERENCES1 Armstrong LE, Hubbard RW, Epstein Y, Weien R. Nonconventional remission of miliaria rubra during heat acclimation: case study. Mil Med 153: 402–404, 1988.Crossref | ISI | Google Scholar2 Buettner K. Diffusion of water and water vapor through human skin. J Appl Physiol 6: 229–242, 1953.Link | ISI | Google Scholar3 Gonzalez RR, Pandolf KB, Gagge AP. Heat acclimation and decline in sweating during humidity transients. J Appl Physiol 36: 419–425, 1974.Link | ISI | Google Scholar4 Van Heyningen R, Weiner JS. A comparison of arm-bag sweat and body sweat. J Physiol 116: 395–403, 1952.Crossref | ISI | Google Scholar5 Weschler L. Viewpoint: Sweat electrolyte concentrations obtained from within occlusive coverings are falsely high because sweat itself leaches skin electrolytes. J Appl Physiol; doi:10.1152/japplphysiol.00924.2007.Link | ISI | Google Scholar Download PDF Previous Back to Top Next FiguresReferencesRelatedInformationCited ByCFTR genotype-related body water and electrolyte balance during a marathon17 August 2015 | Scandinavian Journal of Medicine & Science in Sports, Vol. 26, No. 9Arsenic, Cadmium, Lead, and Mercury in Sweat: A Systematic ReviewJournal of Environmental and Public Health, Vol. 2012Effects of short-term training on thermoregulatory and sweat responses during exercise in hot conditions8 November 2010 | Equine Veterinary Journal, Vol. 42Last Word on Viewpoint: Sweat electrolyte concentrations obtained from within occlusive coverings are falsely high because sweat itself leaches skin electrolytesLouise B. Weschler1 October 2008 | Journal of Applied Physiology, Vol. 105, No. 4 More from this issue > Volume 105Issue 4October 2008Pages 1378-1378 Copyright & PermissionsCopyright © 2008 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.zdg-8179.vpcomm.2008PubMed18838515History Published online 1 October 2008 Published in print 1 October 2008 Metrics
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