Gentle cleansing syndet for daily care of baby's skin?

The approach to infant skin cleansing treatment has gone through significant changes over the years. In earlier days, practices included daily soap baths, baby oil slathers, and heavy powdering. Softer soaps and shampoos were considered safe for infants during the late 1980s; however, research now highlights the advantages of bathing less frequently while using pH-neutral and mild cleansers to protect an already fragile skin barrier. Some experts even suggest that infants should be bathed no more than twice a week, but all agree on the importance of gentle cleansing practices that do not irritate the skin while optimizing its health, especially for those at risk of atopic dermatitis.

Products for washing newborns and infants remain a subject of debate. According to current recommendations, including those provided by the British National Institute for Health, the use of cleansers should focus on mild, non-perfumed soaps, which should only be used if necessary. Numerous recent studies suggest that washing with gentle cleansing syndets is comparable to using plain water in maintaining the skin's acid mantle and reducing fat content. For example, the regular use of home wash gel twice a week during the first eight weeks of life significantly reduced skin pH across all body sites (pH 5.4 – 5.9, compared to the almost neutral pH 6.2 – 7.5 at birth). Lower pH means less bacterial growth and enzyme activity, which is beneficial for the skin barrier).

A new randomized controlled study evaluated the acceptability of a dermatological syndet cleanser on the skin of infants. Group of 180 healthy infants were then randomized into three groups of sixty infants. The first group used the syndet cleanser, the second an alternative liquid cleanser for babies, and the third lukewarm tap water as whole-body washes twice weekly for two weeks. Evaluation was done at baseline and after one and two weeks using clinical dermatological evaluation, instrumental measurement, and parental report. Key assessed parameters included erythema, edema, dryness, scaling, skin moisture, surface pH, trans-epidermal water loss, and hemoglobin levels. Results indicated that none of the cleansing modalities caused important irritation or dryness and no unwanted effects were noted, with parents reporting high tolerability for each group. In conclusion, all cleansing methods were effective and safe for infant skin.

Regular soaps neutralized with sodium hydroxide typically have pH values of 10 – 11 or 8.5 – 10 when partially neutralized with milder alkali amines like triethanolamine. Combo bars with soap as the main cleansing agent have an alkaline pH of 8.5–10 and can drop to 7.5 when soap content is minimal.

Soap-free syndets that align with the skin’s natural pH of 5.5 – 7 cause no disturbance to its balance—making them suitable for cosmetic and baby cleansing bars. Medicated bars may have a low pH of 3.5 – 5 (e.g., iodine-based bars), where acidic conditions ensure stability. Synthetic detergent-based formulations are ideal for medicated cleansing bars due to their ability to maintain a stable, low-pH environment.

Another study aimed to determine the pH values of children's antibacterial soaps and syndets and check if such pH values were indicated on the product labels. The assessment included a total of 90 samples of soap: 67 of them were children's soaps, 17 were antibacterial soaps, and 6 were syndets. The pH values for liquid soaps ranged between 4.4 and 7.9, while syndets were the closest to the ideal slightly acidic range. Meanwhile, the antibacterial soaps showed higher pH levels up to 11.34. Among these, only two soaps indicated pHs on their packaging. The conclusion made from this study is that liquid soaps, especially syndets, are healthier for an infant's tender skin because of their exact pH levels, which assure skin health through the barrier.

Daily syndet bathing does not damage the skin, even in cases of compromised barriers with mild erythema, indurations, or dryness. Because infant skin has higher transepidermal water loss (TEWL), increased water desorption rates, and decreased natural moisturizing factor (NMF), cleansing agents must be gentler than those used for adults to prevent barrier disruption. Even though some instances of irritant contact dermatitis from harsh surfactants have been documented, the occurrence of irritant reactions to properly formulated products intended for infant use is extremely rare (one to three reactions reported for every million units sold). This demonstrates the importance of choosing a mild, well-formulated cleansing syndet for baby’s skin. However, more large-scale, standardized studies are needed to provide stronger, science-backed recommendations in the future.