The effects of urine and incontinence on the skin

The effects of urinary incontinence on skin vulnerability are another neglected area of nursing investigation. Despite the scale of the problem, the effects and prevention of urine exposure on skin barrier disruption has
received limited research attention. The prevalence of urinary incontinence provides an indication of the potential significance of the problem. It is estimated that 200 million people worldwide have significant
urinary incontinence and many more with mild bladder problems, with a high occurrence among people living in institutional settings. Obesity affects 20% of the population in UK (National Audit Office, 2001). It is
a major health problem in most affluent countries and is likely to lead to skin vulnerability due to the formation of skin folds. Children are another vulnerable group; it is estimated that in the UK 500,000 experiencenocturnal enuresis (persistent bedwetting). Although incontinence may not of coursen accompany older age, an increased incidence of multiple disabilities in this group may contribute to reduced ability to maintain continence, making this group vulnerable to skin damage. The skin of an incontinent person will be
exposed to regular contact with urine, sweat and possibly faeces. As such, the skin is vulnerable to chemical irritation by urine and physical effects caused by wetness of the skin that encourages maceration; these can disrupt the skin barrier and lead to breakdown. The decomposition of urinary urea by microorganisms release ammonia to form the alkali, ammonium hydroxide, thereby disrupting the acid mantle. Chemical irritation of the skin may arise from both the rise in alkalinity and bacterial proliferation. Perineal dermatitis may arise from urine exposure, which is characterised by inflammation of the skin, and may include redness, tissue breakdown, oozing, crusting, itching and pain within the perineal area. Faecal incontinence may present even more risk to skin integrity. It is more common in the general population than is often realised and the survey
cited above suggests 5.7% of women and 6.2% of men over 40 years living in their own homes report some degree of faecal incontinence. Overall, 1.4% of adults reported major faecal incontinence (at least several times a month) and 0.7% had disabling incontinence with a major impact on their quality of life. Excess moisture can increase the friction coefficient, making the skin more vulnerable to breakdown due to friction forces. This, coupled with frequent washing of the incontinent patient’s skin, can disrupt skin barrier function by removal of skin lipids and the acceleration of epidermal water loss (further examination is given later). A number of studies reveal a general association between urinary incontinence and pressure sores, but few demonstrate a causal link. For example, a study of nursing home residents by Schnelle et al. (1997) demonstrated that skin problems tend to occur in areas where there has been consistent excessive skin wetness (hydration) through urine exposure. These findings are consistent with supporting experimental evidence that skin exposed to urine due to infrequent pad change can increase the wetness of the skin; the increase in friction and abrasion predisposing it to breakdown. Prolonged exposure to water alone may cause
hydration dermatitis  and prolonged occlusion of the skin (as within a continence product) may reduce skin barrier function  and significantly raise microbial counts and pH.
Consideration also needs to be given to the effects of drying practices related to washing practices. An excessively dry stratum corneum can develop cracks and fissures and can be as ineffective a barrier as an over-hydrated one (Tsai and Maibach, 1999). Dry and scaling skin contributes to the risk of pressure ulcer
development, although only limited evidence has been found. Those with dry or scaling skin have been found to be at least 2.5 times more likely to develop wounds from skin breakdown compared
to a matched control group, based on one of the largest studies (n 5, 193) examining predictors of pressure sores in the community (55–75 years). As a risk factor, dry skin is not reflected in pressure risk scales,
which focus on the key role of moisture. Aside to dry and over-hydrated skin, some patients also develop sore skin in which there is erythema due to inflammatory effects and a damaged skin barrier. Again, the issue of sore skin is another area given scant attention in the literature.