The skin of newborns is more fragile than that of children and adults. Protective measures are important to prevent irritation, infection, and rashes.
What About Infant Skin?
The skin is a complex organ that has a variety of functions. It serves as a protective barrier, assists in thermoregulation, and provides tactile sensation of the world around us. The skin of a newborn, however, is very different from that of a child or an adult. Infants who are born prematurely have particularly sensitive skin.
Infant Skin at Birth
The outermost portion of the skin, the epidermis, is very thin at birth. Full-term infants have 30 percent fewer stratum corneum layers, and they are decreased by 40 to 60 percent in premature infants. Depending on the gestational age, premature skin may even appear translucent. Until skin is fully mature, around the first or second birthday, the epidermis is more permeable and prone to irritation. The middle dermal skin layer of a newborn has less collagen and elastin. These components are important for skin strength and flexibility. Without a sufficient amount, the risk of edema increases, even from minor skin injuries or irritation.
At birth, the skin is covered in a substance called vernix caseosa. This is a cheese-like coating that begins to form at 19 weeks gestation. The vernix consists of mostly water, but also proteins and an oily substance secreted by the sebaceous glands. It thickens until 34 weeks gestation, and protects the developing skin from amniotic fluid irritation. Infants who are born prior to 34 weeks have a thinner layer of vernix.
After birth, newborn skin may appear wrinkled, have lanugo hair, and show signs of peeling by day two to three of life. This is a normal sloughing of the outer stratum corneum, and occurs because the skin is no longer covered by the vernix. Infants born after 42 weeks gestation, or who experienced low intrauterine amniotic fluid, may exhibit excessive skin peeling. After a few weeks, however, this skin desquamation resolves.
The optimal skin pH is four to six. This acidity is important for maintaining the integrity of the stratum corneum, and a healthy skin microbiome. However, infants are born with a skin pH of about seven, and it remains at this level for several weeks. This alkaline environment increases the risk of skin infections, and blocks the production of the lipids that prevent dryness.
Infant Skin Types
In addition to newborn factors, the skin of some infants may appear “more sensitive” than that of others. Some exhibit a temporary skin redness on areas where they are held. This may occur with contact against a caregiver’s skin or clothing. This erythema is not bothersome, and typically fades within minutes. Other infants have dermatographism, developing raised lines or hives when their skin is scratched. This is a histamine-mediated reaction that self-resolves within 30 minutes. Other babies seem to have persistently dry skin. Genetics, water quality, and seasonal temperature changes can contribute to this problem. Some infants have early signs of dryness or irritation on their neck folds area at birth. Over time, areas of the face, arms, legs, and trunk develop the “rough,” erythematous patches of atopic dermatitis. This condition may become chronic, and is associated with the future development of food allergies.
Infant Skin Care Recommendations
– Bathing –
The recommendations on when and how newborns should be bathed have evolved. Currently, the World Health Organization recommends delaying the first bath until six to 24 hours after birth. This allows time for skin-to-skin contact. According to UNICEF, this bonding time is important for calming the baby after birth, and enabling more successful breastfeeding. Leaving the vernix on the newborn’s skin supports temperature regulation, and protects against infections. When a premature infant who has required resuscitative efforts is stable, skin-to-skin time is also recommended. Premature skin is more sensitive to touch than that of full-term infants, and this bonding time helps to reduce the stress of NICU care.
Most the vernix is removed during the first infant bath. Recent studies indicate that immersion baths are less irritating to newborn skin than sponge baths. It is felt that sponges or washcloths create unwanted friction on the delicate skin. Many parents, however, tend do sponge baths at home until the umbilical stump has separated, and, for some boys, until a circumcision has healed.
For most full-term infants, a bath every three days is appropriate during the first few months of life. Premature infant skin is particularly prone to dryness and irritation, so a swaddled bathing technique every four days is recommended. The water temperature should be warm, and the timeframe limited to five to 10 minutes. A non-alkaline infant cleansing product helps to maintain the protective acidic skin pH. After a bath, the baby’s skin should be towel dried as soon as possible to reduce heat loss.
– Moisturizers –
Most newborns do not experience skin problems during the first few weeks of life. When dry skin develops, however, moisturizers provide an external layer of protection. They keep the skin hydrated, and help to maintain its lipid content. In studies where emollients were used during the first month of life, the rates of diaper rash and other skin problems were much lower than in infants who received no skin treatments. Moisturizers are particularly effective for infants with atopic skin, and reduce the flares. In such cases, emollients have the additional benefit of maintaining a low skin pH, and supporting the normal skin microbiome.
Because newborn skin can be sensitive, products with fragrances and irritating preservatives should be avoided. There is increasing concern regarding the effects of parabens on the endocrine system. These preservatives are easily absorbed through adult skin, so it is likely that higher skin absorption occurs in infants. Similarly, phthalates may negatively affect reproductive organs, so products with these ingredients should be avoided. Unfortunately, there is minimal regulation or oversight on what qualifies a “natural” or “sensitive” skincare product. Any suspected adverse skin reactions should be reported to the appropriate health authority.
EVEIL Infant Skin Research Program
Mustela’s 15 year research program to better understand the physiology of infant skin