Development of an Animal Model for Inducing Various Degrees of Severity of Incontinence-Associated Dermatitis.

PURPOSE: The purpose of this study was to describe the biological changes after incontinence-associated dermatitis (IAD) induction by pancreatin in the guinea pigs and to explore the potentially appropriate timing and pancreatin concentration for IAD induction with different severity. DESIGN: In vivo, experimental study. SUBJECTS AND SETTING: An experimental animal model (guinea pig) in a controlled laboratory setting was used for investigation. METHODS: We developed an IAD model in guinea pigs by occluded application of 1%, 5%, and 10% pancreatin solutions for 1, 3, and 5 days, respectively. The irritant was applied to the posterior aspect of shaved guinea pigs. We used an adapted visual scoring system to evaluate IAD and its severity. We also measured differences of the fluid absorption rate as a proxy for transepidermal water loss and enzyme-linked immunosorbent assays of interleukin 2 and interferon-γ expression as indicators of IAD-related inflammation. Analysis of variance (ANOVA) was used to examine group differences. RESULTS: Higher pancreatin concentrations led to more severe skin responses and higher mean visual scale scores, yet the statistically score differences were only observed in the 1% and 5% pancreatin groups after 3 and 5 days of exposure compared with 1 day of exposure (P < .05). The average absorbed fluid rate increased from 1 to 3 days of exposure and reached a plateau at 3 days; significant differences were observed in 3 and 5 days of exposure (P < .05) when compared with 1 day of exposure but not between 3 and 5 days of exposure. CONCLUSIONS: Exposure of a guinea pig animal model to 1%, 5%, and 10% pancreatin solutions over a 3-day period induced IAD with different levels of severity. Additional studies using this model are warranted.