ABSTRACT
The effect of urine and feces on the skin is a contributing factor to the development of incontinent and diaper dermatitis. The objective of this research was to evaluate skin effects of a given urine or fecal sample on the donor child and/or an adult caregiver, both of whom would be exposed to the biological material in course of daily life. Methods: Urine was evaluated under a variety of experimental skin conditions: normal (N), compromised by tape stripping (C), hydrated by prolonged exposure to water via occlusive patch (H), and hydrated/compromised (H/C). After pre-treatment, sites were patched (3 times of 24-h each) with 0.5 ml infant urine, saline (negative control) or 0.3% sodium lauryl sulfate (SLS, positive control). Fecal material was evaluated using a 4-h patch followed by tape stripping of selected sites. Results: In the urine study, a single 24-h patch produced a significant elevation of pH compared to both the negative (saline) and positive (sodium lauryl sulfate) controls for all experimental skin conditions. Erythema produced by urine was intermediate between the negative and positive controls, and significantly different from the negative control on the N and C skin test sites. All three materials produced an increase in hydration of the skin. The single 4-h patch of fecal material produced significant erythema, a significant elevation of pH, and a significant increase in TEWL. Recovery to pre-treatment levels was observed by the next day on sites that received no further treatment. However, on sites patched with fecal material, then further compromised by tape stripping, recovery to pre-treatment levels for erythema and TEWL were delayed. Conclusion: These studies indicate that urine appears to have an inherent low level irritant property when in continuous contact with skin for 24 to 48 hours. With relatively short exposures of 4 hours fecal material causes visible erythema, increases in pH and TEWL, and decreases in stratum corneum resilience to the subsequent insult of tape stripping. Results re-inforce the utility of modern diapers and incontinent products, utilizing superabsorbent materials, to effectively absorb wetness, keeping skin dryer and minimizing adverse skin effects.
ABSTRACT
Objective To investigate the impact of synthetic urine (synurine solution) at differentpH values on skin surface.Methods Sixty-four healthy volunteers were enrolled into this study.Based on the results of lactic acid test and questionaires,these subjects were enrolled as sensitive skin group and normalskin group.The 4-,20-,and 24-hour occlusive patch tests were successively performed with synthetic urine at various pH values (2.0,3.5,5.0,6.5,8.0 and 10.0)on the two groups of volunteers.The distilled waterand 0.25%sodium lauryl sulphate (SLS)served as control.The skin surface pH values were measured bypotable pH meter before,and at 24 h,48 h,72 h after the first patch.Half an hour after the latter three detections of pH values,the skin response was evaluated clinically,as well as by transepidermal water loss (TEWL)and pH values,which were measured by pH-900 pH Meter.Results The responses to these solutions were similar between sensitive and normal skin groups.The order of skin surface pH values measured by the two pH meters was consistent with that of the original solutions.The skin surface pH value was altered by the synthetic urine,and this change was still present at 24 hours after the patches were removed.The TEWL values of skin challenged by synthetic urine were not higher than those by distilled water.The skin responses at 72 hours were more intense to the synthetic urines with pH values of.5,8.0,10.0than to distilled water.CondusionsSynthetic urines with different pH values can alter skin surface pH values,and skin responses to synthetic urines with a pH range 2.0-10.0 are similar to those to distilled water.