Scientific interview -
frequently asked questions at the dermatology clinic
Answered by Dr. Christina Schnopp
Clinic and Polyclinic for Dermatology and Allergology, TU Munich
What is so special about baby skin? Can I use regular skincare products on my baby or does a baby’s skin need special products?
Healthy babies are already born with relatively well-developed skin. During the first few months, however, the top layers of a baby’s skin, like the stratum corneum which has an important barrier function, are much thinner than that of adult skin1,2.The skin cells are smaller and divide faster.2 Sweat and sebaceous glands are not yet fully developed3, meaning that babies cannot yet fully regulate their body temperature through sweating and the fat content of the stratum corneum is lower2.
These structural differences can increase the permeability of a baby’s skin. The transepidermal water loss (“transepidermal” = through the epidermis) as an indication for the barrier function of a child’s skin varies strongly during the first year. It takes at least until a baby’s first birthday before their skin’s barrier function is fully developed.
Compared to adult skin, baby skin can absorb more moisture in less time, but can also lose it again more quickly. One reason for this could be the lower level of natural moisturising substances in the top skin layers of babies under the age of one4.
In the first few days after birth, a baby’s skin has to adjust from a wet environment to a dry environment. During this time, the vernix caseosa, a mixture of fat and dead skin cells that served as a protective layer inside the womb, gradually sheds. From the second week on, the water content of the top skin layer increases quickly.
The pH value of a newborn’s skin is neutral (possibly because of the mildly alkaline amniotic fluid). During the first few days it decreases, but does not yet reach the pH value of adult skin which is necessary for a fully functional ‘acid mantle’5. This higher pH value adversely affects the different enzymes that are responsible for maintaining the skin’s barrier function. This can cause skin irritations, especially in the nappy area.
All of this means that baby skincare products need to meet certain criteria. Since baby skin may be more permeable and the ratio of body surface to weight is much higher than that of adults, the ingredients in baby skincare products must be completely safe. Also, anything that could damage the skin barrier or could impede its development, e.g. by changing its pH value or by dissolving skin fats, must be avoided.
For example, traditional soap bars (alkaline) attack the skin fats and are therefore not suitable for babies.
1) Evans NJ, Rutter N. Development of the epidermis in the newborn. Biol Neonate 1986; 49:74-80.
2) 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. Pediatr Dermatol 2010; 27:125-31.
3) Agache P, Blanc D, Barrand C et al. Sebum levels during the first year of life. Br J Dermatol 1980; 103:643-9.
4) 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. J Invest Dermatol 2008; 128:1728-36.
5) Stamatas GN, Nikolovski J, Mack MC et al. Infant skin physiology and development during the first years of life: a review of recent findings based on in vivo studies. Int J Cosmet Sci 2011; 33:17-24.
