Clinical Review DATE OF PUBLICATION: MAY 2017

Transcription

1 Clinical Review DATE OF PUBLICATION: MAY 2017 PROTECTING BABY S SKIN AT BATH TIME Written by: Mark Greener, BSc (hons), MRSB Reviewed by: The British Skin Foundation Atopic eczema, which usually emerges symptomatically during the first few weeks or months of life,1 affects between 16% and 30% of children in the UK.2 Indeed, the prevalence of eczema is rising, although the reasons underlying the increase are unclear.2 A significant proportion of eczema cases persist into adulthood.2 Figure 1: Skin structure Against this background, a growing number of studies suggest that skin care in early life influences the risk of developing atopic eczema, presumably by facilitating the allergen s access to the deeper layers of the skin. For example, using harsh soap and detergents during a baby s bath time can compromise the skin s barrier function as well as disturbing levels of enzymes, proteins, lipids and micro-organisms on the skin surface, all of which are important for normal dermatological structure and function. In other words, using harsh soap and detergents facilitates the interaction of genetic and environmental factors that influence skin barrier function.2 Therefore, as discussed in this module, the choice of skin care products for infants is critical. The skin consists, broadly, of three layers: the outer epidermis, the dermis and the underlying subcuis (also called the hypodermis), which is comprised mainly of fat and connective tissue. The epidermis consists of four major layers: basal, spinous, granular and stratum corneum. Cells in the spinous and granular layers are attached to corneodesmosomes. These rod-like structures connect the various layers of the epidermis. The stratum corneum, the outermost layer, accounts for most of the skin s physical barrier (figure 1).3 ASKLEPIOS MEDICAL ATLAS/SCIENCE PHOTO LIBRARY Reviewed by: In association with: FOR HEALTHCARE PROFESSIONALS ONLY

2 At regular intervals, the epidermis protrudes into the dermis the rete pegs (figure 1). The suprapapillary epidermis lies between the rete pegs. The junction between the dermis and epidermis is relatively flat in infants and more undulating in adults. 4 Against this background, an industry sponsored study, compared the skin of the lower thigh of 20 healthy mothers and their biological children (3-24 months). The infants stratum corneum and epidermal layers were thinner than those in adults. In addition, the corneocytes (the cells that make up most of the epidermis) and granular cells (which help bind the skin together and produce lipids) were smaller than those in adults. On average, the suprapapillary epidermis and the stratum corneum were 20% and 30% respectively thinner in infants than in adults. On the lower thigh, for instance, the average thickness of the infant and adult stratum corneum was 7.3μm and 10.5μm respectively. 5 Moisture loss An intact skin barrier is a prerequisite to normal dermatological function. For instance, a defective skin barrier increases the rate of water loss through the skin. Indeed, dry skin seems to be one of the first dermatological changes that emerge in babies who develop eczema. 2 TEWL (Transepidermal Water Loss) is a clinical technique that measures the rate that skin loses water. Certain factors potentially influence TEWL such as mild stress, body site and environment, notes an industry funded review. 6 In general, however, TEWL correlates directly with skin barrier function. The higher the TEWL, the weaker the skin barrier. The skin s barrier function develops during the first year of life. Before then, TEWL appears to be higher Epidermal thickness * in infants than adults. In a study, cited in the industry funded review, the average TEWL of 124 children aged 3-12 months was 3- to 5-fold higher, based on measurements made on upper ventral and lower dorsal arms, than in 104 adolescents and adults (aged years). 6 The higher TEWL reflects the weaker barrier function provided by infant skin. Partly because of the reduced barrier function, infant skin absorbs water more rapidly than in adults. The hydration of the stratum corneum appears to be low in neonates born at term and gradually increases over 14 to 90 days, notes the industry sponsored review. 6 The level of skin hydration depends on two main factors: The amount of natural moisturising factor (NMF) The integrity of the hydrophobic (water-repelling) matrix of extracellular lipids in the stratum corneum. 7 NMF aids the uptake of water into the stratum corneum and, in neonates, seem to rebalance ph and hydration of the skin surface. 6, 7 The concentration of NMF seems to be significantly lower in the stratum corneum and upper epidermis (based on measurements taken on the arm) of infants than adults. 6 Lipids in the skin Sebum levels in the skin are high in the first week of life, following the surge in androgens that occurs before birth. However, sebum levels then decline rapidly and infant skin contains less total lipids than that in adults, 4 which could influence the skin s barrier function. For instance, the matrix of extracellular lipids prevents the uncontrolled loss of water and electrolytes from the epidermis. 7 These differences Table 1: Examples of structural and functional differences between infant and adult skin 4, 6 Cell attachments and epidermal cellularity Lipids Melanin Sweat Water content Concentration of NMF ph TEWL * * Some studies suggest no significant differences Infant compared to adult Mixed results, but seems to be higher contribute to the infant s skin lower ability to maintain moisture levels than adults. As a result, infant skin is vulnerable to dryness, irritation, atopic and contact dermatitis. Skin ph Maintaining an acidic ph is essential for normal skin function. The surface of adult skin is acidic (ph between 5 and 5.5). 7 Skin is alkaline at birth (ph of >6). The acid mantle (skin ph <5.0) forms within approximately four days. 8 The elevated ph compared to adults can predispose to inflammatory skin conditions. In addition, using harsh soap and detergents can increase the ph of the skin s outer layers, which potentially compromises skin barrier function. 2 Against this background, another review funded by industry suggests that products used to clean infant s skin should, ideally, not alter the ph of the skin surface. 9 However, baby cleansers typically range from ph 4 to 10, 10 which, in some cases, might affect surface ph sufficiently to alter skin function. For instance, high (alkaline) ph breaks down corneodesmosomes, substances which act like rods to hold skin cells together. Moreover, the enzymes, beta-glucocerebrosidase and sphingomyelinase, are most active at low acid ph. 11 Therefore, a high ph on the skin surface might reduce the lipid content of the stratum corneum. Interestingly, skin ph - even in unaffected areas - is significantly higher in patients with atopic eczema than those with healthy skin. 11 Implications for skin care Cleansing helps remove irritants such as urine, faeces and micro-organisms that could break down skin and increase the risk of, for example, nappy rash, atopic eczema and infections. However, in the 8 weeks after birth, NICE recommends that parents should not add cleansing agents to a baby s bath water. When needed, parents can use a mild non-perfumed soap, which is only cleansing agent suggested by NICE. 12 Nevertheless, an industry funded review notes that some authors contend that there is limited evidence to support the NICE position on infant cleansing. 9 Water, for example, does not remove all oil-soluble contaminants from the skin surface and is a poor ph-buffer. Depending on how often the baby is bathed and the water quality, washing with water alone might dry infant skin. 9 The Mum & Baby Academy is committed to improving antenatal, postnatal and paediatric care by offering free, easyto-use CPD and other resources that help professionals in their daily practice. Mum & Baby Academy 2017 Lifecycle Marketing (M&B) Ltd, Remenham House, 3 Regatta Place, Marlow Rd, Bourne End, Buckinghamshire SL8 5TD. Date of publication: May This material is prepared for training purposes only and is not intended to sell or promote any particular product. The material is intended for healthcare professionals only. The material should not be supplied to non-healthcare professionals. HOW TO COMPLETE THIS CPD MODULE After reading this clinical review, please visit where you can assess your learning with reflective and multiple-choice questions. You can save work in progress and access a CPD learning log. MUM & BABY ACADEMY TEAM Healthcare director: Sunil Singh Clinical editor: Mark Greener BSc (hons), MRSB Design: Paul Stratford Website management: Melanie Reynolds Printed by: Qwerty Ltd, The Markham Centre, Theale, RG7 4PE Contact the team through our website: ACKNOWLEDGMENT Baby Dove funded the preparation of this CPD module and associated materials, which they reviewed for scientific and clinical accuracy. ABOUT THE MUM & BABY ACADEMY The Mum & Baby Academy does not endorse any particular products. The Mum & Baby Academy is an educational initiative by Lifecycle Marketing, who also publish Emma s Diary. Published in association with the Royal College of General Practitioners (RCGP), Emma s Diary is the UK s most trusted and influential communication platform for mums-to-be and new parents. 2 FOR HEALTHCARE PROFESSIONALS ONLY

3 In association with: Figure 2: Coloured scanning electron micrograph of skin taken from a 2-week-old baby. The skin is still adapting to changes from the fluid environment of the womb, to the drier environment of the atmosphere synthetic and detergent ) bar is probably more appropriate than conventional soap. A recent industry sponsored study compared a market leading baby bar, which had a ph of 10, soap bar and a commercial neutral ph syndet bar. The study used a standardised, widely employed test to assess the mildness of the soap and syndet applied to the skin of healthy subjects aged between 18 and 65 years old. 10 EYE OF SCIENCE/SCIENCE PHOTO LIBRARY As mentioned above, products used to clean infants should not alter the ph of the skin surface. 9 Traditional soaps, however, contain detergents derived from saponification, a stage in soap making where a strongly alkaline solution is mixed with a fatty substance (eg vegetable oil or tallow). Tallow is a solid form of rendered beef or mutton fat. A formulation containing oleic, palmitic, stearic, palmitoleic, linoleic and myristic ingredients might indicate that the formulation contains tallow. Alkaline soaps can increase the ph of the skin surface above the ideal range. Soaps might also dissolve skin lipids and other fat-soluble and watersoluble components that contribute to the barrier function. As a result, the review funded by industry argues that soap can cause dryness and irritation. 9 The benefits of liquid cleansers Against this background, in an industry sponsored publication, a consensus panel of paediatricians and dermatologists recommended cleaning neonatal and infant skin using liquid, ph-neutral, or mildly acidic cleansers rather than traditional alkaline soaps. The panel regarded liquid cleansers as preferable to water alone: partly because liquid cleansers clean and hydrate skin better than water alone. 9 In addition, liquid cleansers often contain emollients, which the panel regarded as preferable to cleansing bars. 9 Emollients, the industry funded review argues, protect the integrity of the stratum corneum and maintain skin barrier function. In an appropriate formulation, emollients can supply the stratum corneum with water and lipids, and reduce water loss. In turn, epidermal keratinocytes (the main cell type in the epidermis) use lipids supplied by the emollients to maintain a functional epidermal barrier. 9 These properties make liquid cleansers preferable to water alone. 9 The industry funded review notes that after 8 weeks of life, skin surface ph was significantly lower (less alkali) in healthy, full-term neonates who were bathed with a liquid cleanser compared to those who were cleaned with water alone. Bathing with a liquid cleanser did not significantly alter median TEWL or stratum corneum hydration compared to water alone. In previous studies, soaps produced a statistically significant loss of fat from infant skin. The liquid cleanser did not significantly change levels of skin sebum. Using a liquid cleanser was well tolerated during the first 8 weeks of life. 9 Soap versus syndet If patients prefer a bar, a syndet (a term coined from Perhaps not surprisingly, the neutral ph syndet bar was milder than the ph 10 baby soap in the industry sponsored study. The study also showed, however, that neutral ph bars and liquid body wash formulations were milder than formulations that were close to skin s physiological ph. This might reflect increased skin dryness arising from the interaction between anionic surfactants and stratum corneum that occurs under weak acidic conditions. In other words, the likelihood that a cleansing bar or liquid will dry the skin depends on the surfactants included in the formulation and their interaction with the stratum corneum under the ph associated with normal use. As infant skin is especially vulnerable, these effects are likely to be even more important when bathing a baby. 10 Conclusion A growing number of studies suggest that skin care in early life potentially influences the risk of eczema. For example, using harsh soap and detergents can compromise skin barrier function. 2 Although widely advocated for cleaning, notes an industry funded review, water does not removal all oil-soluble skin surface impurities, is a poor ph-buffer and in some cases might dry infant skin. 9 Against this background, a consensus panel recommended, in an industry sponsored paper, that caregivers use liquid, ph-neutral, or mildly acidic cleansers rather than traditional alkaline soaps on neonates and infants. The panel regarded liquid cleansers as preferable to water alone. In addition, liquid cleansers often contain emollients, which protect the integrity of the stratum corneum and maintain skin barrier function. 9 Infants have a greater ability to restore their barrier function than adults. 4 Nevertheless, the choice of skin care products for infants is critical and might help tackle the rising number of cases of eczema. REFERENCES 1. British Skin Foundation Eczema Available at: uk/skininformation/atozofskindisease/eczema.aspx Accessed March Thomas K, Batchelor J, Bath-Hextall F et al. A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease. Programme Grants Appl Res 2016;4:DOI /pgfar Visscher M and Narendran V The ontogeny of skin. Advances in Wound Care 2013;3: Oranges T, Dini V, and Romanelli M Skin physiology of the neonate and infant: Clinical implications. Advances in Wound Care 2015;4: Stamatas GN, Nikolovski J, Luedtke MA et al. Infant skin microstructure assessed in vivo differs from adult skin in organization and at the cellular level. Pediatric Dermatology 2010;27: Nikolovski J, Stamatas GN, Kollias N et al. Barrier function and water-holding and transport properties of infant stratum corneum are different from adult and continue to develop through the first year of life. Journal of Investigative Dermatology 2008;128: Fluhr JW, Darlenski R, Lachmann N et al. Infant epidermal skin physiology: Adaptation after birth. British Journal of Dermatology 2012;166: Jackson A Time to review newborn skincare Infant 2008;4: Telofski LS, Morello AP, Mack Correa MC et al. The infant skin barrier: Can we preserve, protect, and enhance the barrier? Dermatology Research and Practice 2012;2012:DOI: /2012/ Hawkins S, McGuiness H, Combs K et al. A comparison of low (ph 5.5) and neutral ph cleansers on skin dryness: considerations for baby skin cleansing Poster presented at: 2016 Asian Dermatological congress. Available at: Amitabha.pdf Accessed March Cork MJ, Danby SG, Vasilopoulos Y et al. Epidermal barrier dysfunction in atopic dermatitis. Journal of Investigative Dermatology 2009;129: NICE Postnatal care up to 8 weeks after birth: Clinical guideline Published: 23 July 2006 Available at: nice.org.uk/guidance/cg37 Accessed March TO COMPLETE YOUR CPD, LOG ONTO: FOR HEALTHCARE PROFESSIONALS ONLY 3

4 ADVERTORIAL In association with: Baby Dove: Empowering parents and protecting delicate skin Infant skin is so delicate that using harsh soaps and detergents at bath time can disturb normal dermatological structure and function. 1 The new Baby Dove range offers products, from a baby bathing bar to baby lotions, that go beyond mildness to help keep infant s skin healthy. The Baby Dove range is designed scientifically to protect baby s delicate skin at bath time. The entire Baby Dove range is suitable for newborns and all products have been dermatologically tested and approved by paediatricians, ophthalmologists and dermatologists. For instance, leading paediatricians and dermatologists now recommend cleaning neonatal and infant skin using liquid, phneutral, or mildly acidic cleansers rather than traditional alkaline soaps. 2 Liquid cleansers clean and hydrate skin better than water alone and often contain emollients, which protect the integrity of the stratum corneum, nourish the skin with lipids and maintain skin barrier function. 2 The Baby Dove Head to Toe wash, for example, helps replenish the important nutrients that help to retain skin s natural moisture. The liquid cleansers in the Baby Dove range are as mild as water with added moisturising care. In addition, using harsh soaps and detergents alter skin ph, which potentially compromises barrier function. 1 So, products used to clean infant s skin should, ideally, not alter the ph of the skin surface. 2 However, baby cleansers typically range from ph 4 to 10, 3 which, in some cases, might affect ph sufficiently to alter skin function. In contrast, Baby Dove liquid cleansers, shampoo and bathing bars are ph neutral. Their weaker barrier function and thinner skin than in adults means that infant skin is especially prone to irritation by chemicals or penetration by allergens. So most of the Baby Dove range is hypoallergenic. The Baby Dove lotion soothes dry skin from the first use and provides allday moisture that leaves baby skin feeling soft. With Baby Dove products that gently nourish and care for infant skin, you can empower parents to care for their baby in their own way. References: 1. Thomas K, Batchelor J, Bath-Hextall F et al. A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease. Programme Grants Appl Res 2016;4:DOI /pgfar Telofski LS, Morello AP, Mack Correa MC et al. The infant skin barrier: Can we preserve, protect, and enhance the barrier? Dermatology Research and Practice 2012;2012:DOI: /2012/ Hawkins S, McGuiness H, Combs K et al. A comparison of low (ph 5.5) and neutral ph cleansers on skin dryness: considerations for baby skin cleansing Poster presented at: 2016 Asian Dermatological congress. Available at: Accessed February 2017 TO COMPLETE YOUR CPD, LOG ONTO: FOR HEALTHCARE PROFESSIONALS ONLY 4

5 Learning Log PROTECTING BABY S SKIN AT BATH TIME VISIT TO COMPLETE THIS CPD Name Date completed Method (please tick) Independent learning Participatory learning Please tick the relevant parts of the Revalidaton Code Number of hours spent on this CPD module (Please indicate the number of hours for any participatory learning) Prioritise people Preserve safety Reviewed by: The British Skin Foundation Practise effectively Promote professionalism and trust Relevance to practice Your Mum & Baby Academy unique code (Required to validate your participation) In association with: Mark Greener BSc (Hons), MRSB Clinical Editor Mum & Baby Academy Disclaimer: This CPD Learning Log reflects data and answers provided by the user. It does not imply approval, verification or endorsement by the Mum & Baby Academy or its associated companies.

6 How often do you encounter the topic of this CPD? How often do you proactively offer advice about the subject of this CPD? What questions did the CPD raise that you d like to investigate further? How will this CPD change your practice? What barriers may you need to overcome? The Mum & Baby Academy is a free learning channel dedicated to the needs of antenatal healthcare professionals, produced by Lifecycle Marketing. Lifecycle Marketing also publish Emma s Diary in association with The Royal College of General Practitioners. We are committed to improving the health and wellbeing of mothers and infants. Our approach is to provide clinically robust, independently reviewed, accessible CPD and other resources that support daily practice. Our content undergoes rigorous clinical review by leading academic midwives and health visitors, and our user friendly website mumandbabyacademy.co.uk allows professionals to assess learning, save work in progress and download CPD learning logs for revalidation.