pH and Microbial Infections.

Maintenance of an acidic stratum corneum pH is a major component of the skin's protective system and creates a hostile environment for colonization with pathogenic microorganisms. This barrier can however be overcome on healthy and in particular on compromised skin. Mycosis, diaper/incontinence dermatitis and wound healing are examples of cases where microbial infection is promoted by the altered skin conditions or environment. Fungi have a complex system that senses ambient pH that leads to metabolic responses allowing adhesion, growth and invasion, as microbial metabolites further increase skin pH resulting in a clinically manifest infection (mycosis). Diabetic patients with a higher pH in intertriginous areas are particularly vulnerable to candidiasis. In diaper and incontinence dermatitis, the increase in skin pH and damage to the skin barrier function is triggered by the contact with urine and faeces with or without occlusion and maintained by host and microbial enzymes and metabolites. This leads to the reduction of the protective resident microflora and fungal overgrowth, mostly with Candida albicans. Skin care with slightly acidic products may help to prevent and treat this kind of dermatitis. Wound healing is a complex sequence of biologic events correlated with ambient pH, which influences the different phases of the healing process. The pH determines the appropriate activity of immune cells and key enzymes as well as biofilm formation. Chronic wounds emerging from the disruption of the healing process are characterized by a neutral to slightly alkaline pH and may benefit from wound pH monitoring and therapeutic acidification.

Skin Care Products: Age-Appropriate Cosmetics.

In order to maintain skin in "good condition" one can use cosmetic products. Importantly, those skin care products should fulfil specific requirements for specific life phases and specific skin conditions. In this review, we focused on 2 different age groups - namely, infants and the elderly - as well as on 2 specific skin conditions occurring in both age groups - very dry skin (Xerosis) and hyperhydrated skin (diaper rash). The goal in both conditions should be to maintain skin surface in its physiological acidic state, which is in turn crucial for the permeability barrier function, stratum corneum integrity/cohesion and antimicrobial defense. Skin care products formulated with an effective buffer system at a more acidic pH, for example 4, may be the best option to improve the acid mantle and skin barrier function and thus keep the skin in "good condition."

Cas 2015.3. Lactant de 9 mesos amb lesió perianal / No disponible

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Relationship between skin barrier function in early neonates and diaper dermatitis during the first month of life: a prospective observational study.

Diaper dermatitis, a common skin problem in newborn infants, is characterized by poor functioning of the skin barrier. This study aimed to elucidate the relationship between skin barrier function in 4-day-old infants and the occurrence of diaper dermatitis during the first month of life. We recruited healthy Japanese infants born at 35 weeks of gestation or more. We measured indicators of skin barrier function, namely skin pH and transepidermal water loss, in 4-day-old infants on four places on the body. Individual characteristics were recorded from the infants' medical charts. The presence of diaper dermatitis was judged using the diaper rash and erythema scoring scale, which was based on daily recording of the infants' skin condition by their parents. The parents also filled out a questionnaire 1 month after birth regarding stool frequency and certain external factors. The association between diaper dermatitis and skin barrier function was assessed using multiple logistic regression analysis. The analysis included 88 infants. The incidence of diaper dermatitis was 25.0%. After adjusting for stool frequency for 1 month we noted that high pH on the inner arm skin in 4-day-old infants increased the risk of diaper dermatitis during the first month of life (adjusted odds ratio 3.35 [95% confidence interval = 1.12, 10.04]). Early neonatal skin pH may predict the risk of diaper dermatitis during the first month of life. Our results may be useful in devising strategies to prevent diaper dermatitis.

Documentation of impaired epidermal barrier in mild and moderate diaper dermatitis in vivo using noninvasive methods.

The presence of irritants from feces and urine with the concurrent mechanical friction and occlusion creates an environment in the diapered area that renders the skin prone to diaper dermatitis. Besides being a source of discomfort to the infant, these skin irritations pose a risk of secondary infections. In this study, we used noninvasive in vivo techniques to define measurable parameters that correlate with diaper dermatitis pathophysiology. In 35 infants (16 with mild or moderate and 19 without diaper dermatitis) we compared skin of diapered areas afflicted with diaper dermatitis to lesion-free diapered sites and to skin outside the diapered area (thigh). Our findings show significantly elevated cutaneous erythema, pH, and hydration, with significantly compromised water barrier function in involved areas compared to nonlesional sites both within and outside the diapered area. Furthermore, skin pH in nonlesional diapered skin for the diaper dermatitis cohort was significantly higher compared to the nondiapered sites. These observations are consistent with the current understanding of pathological skin changes in diaper dermatitis. In this study, we demonstrate that noninvasive methods can document relevant parameters to diaper dermatitis in vivo.

Review of methods used for quantifying excess water in over-hydrated skin using evaporimetry.

BACKGROUND: Advances in diapers and skin barrier products are often aimed at reducing water penetration of the skin to prevent diaper dermatitis and evaporimetry has commonly been measured to quantify excess water in the skin. The aim of this study was to critically review the methods used to measure water vapour flux density (WVFD) using evaporimetry in order to identify a standardised methodology. METHODS: We used MEDLINE (1980-2008) and hand searching to identify published papers that used evaporimetry to measure WVFD when the skin has been exposed to water/saline/urine. We compared the papers with respect to subjects, sites, methods of hydrating the skin, the conditions of logging, timing and analysing the evaporimetry data. RESULTS: We identified 10 papers. Methods and techniques for measuring WVFD and analysing data varied considerably between studies and it was not possible to identify a standardised method. The main sources of error and variation are discussed. CONCLUSION: Little work has been carried out to establish the optimum methods and techniques needed to minimise variation in measurements of WVFD using evaporimetery. There is a need to develop more robust, standardised methods and to demonstrate their reliability for further work.

Absorption and efficacy of miconazole nitrate 0.25% ointment in infants with diaper dermatitis.

BACKGROUND: The potential for toxicity from systemic absorption of topical miconazole in infants is a concern. OBJECTIVE: To assess the relative safety of 0.25% miconazole based on the amount absorbed through the skin of infants with diaper dermatitis after multiple applications. METHODS: Of 24 infants with moderate to severe diaper dermatitis, 19 received 0.25% miconazole nitrate ointment and 5 received 2% miconazole nitrate cream for 7 days at each diaper change and after bathing. Blood samples were collected prior to treatment and after 7 days. RESULTS: In the 0.25% treatment group, blood concentrations of miconazole were nondetectable (< 1 ng/mL) in 83% (15/18) and minimal (3.0 to 3.8 ng/mL) in 17% (3/18). Samples were missing for one patient. For the 5 infants in the 2% treatment group, miconazole concentration was nondetectable in 20% (1/5) and less than 7.4 ng/mL in 4 infants. No adverse events were noted. CONCLUSIONS: Systemic absorption of 0.25% miconazole nitrate ointment was minimal, demonstrating its safety in the treatment of moderate to severe diaper dermatitis.

Hydration vs. skin permeability to nicotinates in man.

BACKGROUND/AIMS: Prolonged skin occlusion increases stratum corneum water content and often increases skin permeability and irritant dermatitis. As skin wetness from wearing diapers is considered an important factor favouring the onset of diaper dermatitis, optimal diapering might decrease skin hyperhydration and dermatitis. Our aim is to define the quantitative relationship between nicotinate ester (a model penetrant) skin permeability and hydration, as measured by water evaporation rate (WER), decay curves (at individual time points) and WER-area under the curve (WER-AUC); and also to determine the level of skin hydration and skin permeability to nicotinates following a diapering simulation. METHODS/RESULTS: Nine healthy Caucasian adult women were enrolled after a prescreening procedure (time to peak redness response to nicotinate); each received three wet occlusive patches for different exposure times (10 min, 30 min, and 3h) and two wet model diapers (3 and 8 h). Prior to patching or diapering of forearms, basal values of WER, skin blood flow volume (BFV), capacitance (Cap) and redness (a*) were measured on premarked sites (a, b, c and d). Immediately, following occlusive patch or diaper removal, 20 microL of each nicotinate (methyl and hexyl nicotinate) was applied to its respective site (a or b). The WER and Cap readings were recorded at designated sites (c and d) with the following intervals after nicotinate applications: 0, 5,10,15 and 20 min. The a* and BFV measurements were made on each nicotinate challenged site (a and b) with the following intervals after nicotinate applications: 5, 10, 15, 20, 30, 40, and 60 min. RESULTS: WER-AUC and thus, skin hyperhydration, increased with occlusive patch and diaper exposure time, but there was no statistical difference between 3 and 8h diaper sites. All patched sites had significantly (P<0.05) increased hydration in comparison to control sites (undiapered or unpatched skin). Cap increased with occlusion time with patches, but not with diapers. The degree and time-course of redness from nicotinates did not vary with extent of skin hydration, but was significantly increased compared to non-hydrated skin. BFV-AUC did not show a significant increase between diapers at 3 and 8h sites; the BFV-AUC values varied on the patched sites, but some were significantly (P<0.05) higher than control site. CONCLUSION: Wet patches and diapers increased skin hyperhydration proportional to exposure time. Permeation of nicotinates was increased for hydrated skin vs. control, even after only 10 min of patch exposure. For these model permeants, we found no evidence of increased permeation rates with increased hyperhydration, once a relatively low threshold of hyperhydration was achieved (e.g. that reached after a 10 min wet patch). The data showed no meaningful differences in permeation following either diapering simulation and also suggested that the WER-AUC method was superior to capacitance for measuring the absolute extent of hyperhydration. We believe this is a suitable model for evaluating the quality of diaper product performance, as well as in pharmacologic assays of occlusive therapy.

Association of skin wetness and pH with diaper dermatitis.

The strength of the association between diaper dermatitis and measurements of skin wetness and skin pH was evaluated by statistical analysis of four diaper trials involving 1601 infants. Although the strength of the association between skin wetness and diaper dermatitis was greater than that between skin pH and diaper dermatitis, increases in wetness and pH were both significantly associated with elevated mean grades for diaper dermatitis. The skin environment least likely to be associated with diaper dermatitis is one in which increases in both skin wetness and skin pH are minimized.

Hair zinc, scalp hair quantity, and diaper rash in normal infants.

Hair zinc concentration was determined by atomic absorption spectrophotometry in 308 normal newborn infants and 199 normal infants aged one to twelve months. Hair zinc concentration declined from 204 micrograms/gm at birth to 112 micrograms/gm at age eight months, and then rose to 144 micrograms/gm at age twelve months. Diaper rash was significantly associated with reduced hair zinc, and infants with the least hair had lower zinc levels than infants with the most hair. The data indicate that hair loss and diaper rash found in normal infants is significantly associated with a reduction in hair zinc concentration.

Metabolic alkalosis secondary to baking soda treatment of a diaper rash.

A 4-month-old infant was seen with hypokalemic metabolic alkalosis that was associated with prior application of liberal amounts of sodium bicarbonate (baking soda) to a diaper rash. After exclusion of other etiologies of the infant's acid-base disturbance, a complete resolution occurred following discontinuation of the baking soda applications. This case report provides a reminder of the significant side effects that may result from the excessive use of a seemingly harmless household substance.