Effects of Liquid and Bar Soaps on the Skin of Brazilian Newborns: A Randomized Controlled Trial.

INTRODUCTION: Compared to adults, newborns' skin has a thinner epidermis and stratum corneum with decreased hydration levels, higher transepidermal water loss, and a pH variation between 5.5 and 7.5. These characteristics can predispose to the occurrence of dryness, infections, and dermatological conditions. Water and liquid soap with adequate formulation have shown to be beneficial and safe for newborns' skin. However, studies evaluating the effect of bar soap, products widely used in Brazil and Latin America, are unknown. Therefore, the objective of this study was to compare the effects of liquid and bar soaps on the term newborns' skin. METHODS: This randomized controlled, parallel, single-blind clinical trial was conducted at a public university hospital in São Paulo, Brazil. 100 healthy term newborns with no congenital anomalies, acute diseases, or dermatological conditions were randomized to use liquid soap (experimental group) or bar soap (control group). Skin pH, transepidermal water loss, stratum corneum hydration, sebum content, and skin condition were assessed before and after the first bath, at 48 h, 14 days, and 28 days after birth. These evaluations were performed on the forearm, abdomen, buttocks, and thigh. In addition, the mother's perception of soap use was also evaluated. RESULTS: Data of 100 newborns were analyzed by intention to treat. The rate of retention was 53%. Newborns exposed to the liquid soap presented significantly better skin acidification (p < 0.001) and significantly better stratum corneum hydration (p < 0.001) than the skin of newborns exposed to the bar soap, regardless of the area evaluated. There were no significant differences in transepidermal water loss, sebum content, dryness, erythema, or skin breakdown and the mother's perceptions of the use of the soaps. CONCLUSION: Newborns in the experimental group presented better skin acidification and stratum corneum hydration when compared to newborns in the control group.

Efeito de sabonete líquido e em barra na pele de recém-nascidos a termo saudáveis: ensaio clínico randomizado / Effect of liquid and bar soap on the skin of healthy full-term newborns: a randomized clinical trial

Introdução. A pele do recém-nascido (RN) é mais fina, tem maior perda de água transepidérmica (TEWL), e menor hidratação do estrato córneo (SCH), comparada a dos adultos; seu pH varia entre 5,5 e 7,5. Tais características predispõem a ressecamento, infecções e doenças dermatológicas, como a dermatite atópica (DA). Sabonetes adequados previnem ou minimizam essas alterações e favorecem o amadurecimento da pele. Não há disponíveis estudos sobre o efeito dos sabonetes comumente usados no Brasil na pele de RN. Objetivos. 1 - Analisar as informações de rotulagem, características físicas e físico-químicas de sabonetes usados em RN; 2 - Comparar o efeito do sabonete líquido e em barra sobre o pH, TEWL, SCH, teor de sebo e integridade da pele de RN a termo saudáveis; 3 - Verificar a relação entre variáveis demográficas e clínicas sobre os parâmetros biométricos da pele de RN a termo no período neonatal. Métodos. Tese desenvolvida em três etapas: 1- Estudo quantitativo e descritivo, com 17 sabonetes comercializados em São Paulo - Brasil. Foram analisados: tipos de tensoativos e testes de segurança do rótulo; e coloração, intensidade da fragrância e pH no laboratório. 2 - Ensaio clínico randomizado, paralelo, unicego, conduzido no Hospital Universitário da Universidade de São Paulo (HU/USP) com aprovação do Comitê de Ética em Pesquisa da Escola de Enfermagem da USP e do HU. 100 RN a termo saudáveis foram randomizados ao uso de sabonete líquido (grupo experimental) ou de sabonete em barra (grupo controle). O pH da pele, a TEWL, a SCH, o teor de sebo e a condição da pele foram avaliados antes e após o primeiro banho, às 48 horas, 14 e 28 dias após o nascimento, em cinco regiões corporais. Foi avaliada, também, a percepção das mães sobre o uso do sabonete. 3- Estudo longitudinal e prospectivo, quantitativo, secundário ao ensaio clínico randomizado, que analisou a associação entre variáveis demográficas e clínicas e parâmetros biométricos da pele. Resultados. Os resultados estão em três artigos. 1 - Verificou-se que os sabonetes comerciais tinham tensoativos com potencial de irritação baixo, ou moderado, e fragrância com intensidade variável. Quatro sabonetes líquidos e um em barra combinado apresentaram valores de pH próximos ao da pele do RN. 2 Observou-se valores de pH mais acidificados e maior hidratação na pele com o sabonete líquido. Não houve diferenças significativas na TEWL, teor de sebo, condição da pele e percepções das mães. 3 - Constataram-se associações: da TEWL com tipo de parto, raça/cor, idade gestacional, sexo e tempo; da SCH e histórico familiar de DA, raça/cor, idade gestacional e tempo; do teor de sebo com o histórico familiar de DA e o tempo. Conclusões. Há sabonetes disponíveis no mercado que não atendem critérios para a homeostase da pele do RN, apresentando potencial de irritação moderado, pH diferente do pH da pele e fragrância em intensidade variável. O sabonete líquido mostrou maiores benefícios que o sabonete em barra na pele do RN. Variáveis clínicas e demográficas influenciaram os parâmetros avaliados da pele, demandando estudos amplos sobre o tema.

Introduction. The skin of a newborn (NB) is thinner, has greater transepidermal water loss (TEWL), and less hydration of the stratum corneum (SCH) compared to adults skin, and its pH varies between 5.5 and 7.5. These characteristics predispose the skin to dryness, infections and dermatological diseases such as atopic dermatitis (AD). Suitable soaps prevent or minimize these changes and favor the maturation of the skin. To our knowledge, there are no studies regarding the effect of soaps commonly used in Brazil on the skin of newborns. Aims. 1 - Analyze the labeling information, physical and physical-chemical characteristics of soaps used on newborns; 2 - Compare the effect of liquid and bar soap on the skin pH, TEWL, SCH, sebum content and skin integrity of healthy newborns; 3 - Verify the relationship between the demographic and clinical variables on the biometric parameters of the skin of newborns in the neonatal period. Methods. This thesis was developed in three stages: 1- A quantitative and descriptive study analyzing 17 soaps sold in São Paulo - Brazil. The types of surfactants and label safety tests; and color, fragrance intensity, and pH were analyzed in the laboratory. 2 A randomized, parallel, single-blind clinical trial conducted at the University Hospital of the University of São Paulo (HU/USP) with approval from the Research Ethics Committee of the USP School of Nursing and the HU. 100 healthy full-term newborns were randomized to use liquid soap (experimental group) or bar soap (control group). Skin pH, TEWL, SCH, sebum content and skin condition were evaluated before and after the first bath, 48 hours, 14 and 28 days after birth, in five regions of the body. The mothers' perceptions of the use of soap were also evaluated. 3- A longitudinal and prospective, quantitative study, secondary to the randomized clinical trial, which analyzed the association between demographic and clinical variables and biometric parameters of the skin. Results. The results are described in three articles. 1 - It was found that commercial soaps had surfactants with low or moderate irritation potential and fragrances with varying intensities. Four liquid soaps and one combined bar showed pH values close to that of the newborn's skin. 2 - More acidified pH values and greater skin hydration were observed with liquid soap. There were no significant differences in TEWL, sebum content, skin condition and the mothers' perceptions. 3 - Associations were found: from TEWL with type of delivery, race/color, gestational age, sex and time; SCH and family history of AD, race/color, gestational age and time; tallow content with AD family history and time.|a The types of surfactants and label safety tests; and color, fragrance intensity, and pH were analyzed in the laboratory. 2 A randomized, parallel, single-blind clinical trial conducted at the University Hospital of the University of São Paulo (HU/USP) with approval from the Research Ethics Committee of the USP School of Nursing and the HU. 100 healthy full-term newborns were randomized to use liquid soap (experimental group) or bar soap (control group). Skin pH, TEWL, SCH, sebum content and skin condition were evaluated before and after the first bath, 48 hours, 14 and 28 days after birth, in five regions of the body. The mothers' perceptions of the use of soap were also evaluated. 3- A longitudinal and prospective, quantitative study, secondary to the randomized clinical trial, which analyzed the association between demographic and clinical variables and biometric parameters of the skin. Results. The results are described in three articles. 1 - It was found that commercial soaps had surfactants with low or moderate irritation potential and fragrances with varying intensities. Four liquid soaps and one combined bar showed pH values close to that of the newborn's skin. 2 - More acidified pH values and greater skin hydration were observed with liquid soap. There were no significant differences in TEWL, sebum content, skin condition and the mothers' perceptions. 3 - Associations were found: from TEWL with type of delivery, race/color, gestational age, sex and time; SCH and family history of AD, race/color, gestational age and time; tallow content with AD family history and time. Conclusions. There are soaps available on the market that do not meet the criteria for the homeostasis of newborn skin, presenting moderate irritation potential, pH different from skin pH and fragrance in varying intensity. Liquid soap showed greater benefits than bar soap on newborn skin. Clinical and demographic variables influenced the evaluated skin parameters, requiring extensive studies on the subject.