Prolonged exposure to caustic bodily fluids can lead to maceration and breakdown of the skin physical barrier. Incontinence-associated dermatitis (IAD), skin damage from urine or feces exposure characterized by inflammation, rash or blistering, and erosion of the outermost layers of the skin, is prevalent in geriatric populations. IAD can cause considerable pain and morbidity and lead to secondary infections. Skin protectants reduce contact with fluids, soothe irritation, and promote healing and barrier restoration. The study goal was to compare the barrier properties of two skin care products, one paste-like product containing petrolatum and zinc-oxide* and another liquid formulation without active ingredients$.
To address this goal, test sites were marked on an excised, ventral porcine skin flap and divided into random treatment groups. Fifteen minutes after application, the products were gently removed. A foam pad containing methylene blue dye was compressed on the surface for 15 seconds, digital images were obtained, and the optical density (OD) of each test site was determined using densitometry.
Using this strategy, products that create a moisture barrier will decrease dye penetration into the skin and have a higher OD; those that degrade the normal skin barrier will have opposite characteristics. The mean OD was 45.59, 115.51, and 40.00 calibrated OD units, for untreated control, paste*, and liquid spray$, respectively. Pairwise comparisons with Bonferroni correction following non-parametric Kruskal-Wallis ANOVA (χ_2^2=27.1876, p<0.0001) show a statistically significant difference in OD of paste-treated* and control (DSCF 5.8801, p<0.0001) and the cleanser$-treated (DSCF=4.1251, p=0.0099) skins. While the OD of the paste-treated* skin was more than 2.4-times the control (t13.106=7.88, p<0.0001), the cleanser$-treated skin had an OD 12 percent lower than control (t19.055=-3.23, p=0.0022).
Taken together, these findings demonstrate that of the two products tested, only the petrolatum and zinc-oxide-containing paste* created a protective moisture barrier on the skin surface.