Time to Occurrence of Incontinence-Associated Dermatitis: An Experimental Animal Study.

Objective: To establish an animal model of Incontinence-Associated Dermatitis (IAD) and investigate inflammatory factor changes to determine the time frame for IAD onset. Methods: Twenty-eight male SPF mice were randomly assigned to four groups. Gauze soaked in synthetic fecal solution was applied to the dorsal and ear skin. Based on exposure duration, the groups were designated as the normal, 0.5h, 2h, and 4h groups. At the end of the experiment, IAD severity was assessed, and ear edge thickness was measured. Blood was collected via the eyeball, and IL-1α, IL-6, and TNF-α levels were measured using enzyme-linked immunosorbent assay. Hematoxylin and eosin staining of dorsal skin samples was performed to analyze early pathological changes. Results: No moderate to severe IAD was observed in any group. However, ear edge thickness increased significantly after 0.5h. Mild inflammatory cell infiltration was noted in the 0.5h group, with more severe infiltration in the 2h and 4h groups. Inflammatory factor levels were higher in the 0.5h, 2h, and 4h groups than in the normal group. Conclusion: The IAD model established using synthetic fecal exposure effectively facilitates mechanistic research. Skin tissue became loose and edematous, with a significant increase in inflammatory factors within 0.5h. These findings suggest that fecal contamination should be removed within 0.5h to prevent skin damage. Additionally, IL-1α, IL-6, and TNF-α are promising biomarkers for IAD-associated skin injury.