Cover story

Back to basics: Caring for the newborn's skin

By Anna K. Mendenhall, MD, and Lawrence F. Eichenfield, MD

Parents look to pediatricians for advice on bathing their newborn and avoiding diaper rash. Discolorations and lesions (usually benign) are another concern. This review also updates the best way to care for the umbilical cord and addresses special skin-care considerations in premature infants.

At birth, the infant emerges from an aqueous environment to a dry one. The term neonate's natural covering, the vernix, is wiped off or shed, and as the skin evolves it protects the individual from water loss, trauma, absorption of toxins, and infection. The skin also helps to regulate the infant's temperature in a world that is generally much colder than what it was used to in the uterus. Finally, the skin must contribute to neurosensory perception and immunologic surveillance. How can we best care for this vital organ in the first months of life? How does the skin of a premature infant differ from that of a term infant? How should we advise parents on the care of the umbilical cord? What common skin problems should parents be aware of? In answering these questions, we need to keep in mind that there are many ways to skin (care for) a baby.

Special considerations

Before addressing general guidelines on caring for the skin of the newborn, we will discuss the special needs of preterm infants and how to care for the umbilical cord.

Preterm infants face many obstacles during the transition to life outside the uterus. Problems associated with skin immaturity are evident at birth and may affect how well the infant fares. The thickness of infant skin is 40% to 60% of that of adult skin, and in preterm infants the epidermis, dermis, and subcutaneous fat are even thinner than in full-term infants. The skin of infants of very low gestational age is markedly thin, and quite translucent (Figure 1). The stratum corneum, which becomes fully keratinized between 32 and 34 weeks' gestation, is immature in infants born before that time. Because of this immaturity, the infant loses an enormous amount of fluid through the skin: Infants weighing less than 1,000 g have approximately 65 mL/kg/d of transepidermal water loss (TEWL), and those weighing 1,750 to 2,000 g have about 30 mL/kg/d of TEWL. This loss of water may affect thermal stability, hydration, and electrolyte balance. TEWL has been decreased in premature infants with polyurethane wraps, humidified air, and application of ointment. The skin's barrier function also is compromised by prematurity. The infant becomes more susceptible to trauma and systemic absorption of topical substances.¹ Immature skin is vulnerable to infection and damage from monitor leads and procedures that often confront infants in intensive care.

Although studies have shown that the skin matures rapidly in the two to three weeks after birth, the most recent research indicates that in infants of very low gestational age skin function may be compromised for a longer time than was thought. A study using low-frequency impedance spectroscopy and TEWL measurements shows that in infants of 25 weeks' gestation and less, skin barrier function was immature for significantly longer than four weeks and, in some, for as long as eight weeks after birth.² The delay in skin maturation increases these infants' risk for secondary problems, such as opportunistic infection, mechanical fragility, and absorption of topical agents.

Application of emollients such as Aquaphor, a mixture of white petroleum in mineral oil, mineral wax, and wool wax alcohol, decreases TEWL by 67% within 30 minutes and six hours later still confers a 34% reduction in TEWL, a study by Nopper and colleagues shows.³ The Nopper study also shows that ointment application in premature infants lowers rates of positive blood and cerebral spinal fluid cultures, a major benefit. Only 3.3% of treated infants had positive blood cultures, compared with 26.7% of infants who were not treated with ointment. Significantly better skin-condition scores and less bacterial colonization also were associated with ointment use. The Nopper report is based on a small number of subjects; a multicenter trial by the Vermont Oxford Neonatal Network is studying the routine use of topical ointment in large numbers of preterm infants.

White petrolatum (Vaseline) is another useful skin emollient. It poses little risk of allergic sensitization. Studies in mature adult skin experimentally damaged by acetone show that petrolatum ointment penetrates into intercellular spaces of the stratum corneum and improves barrier function. A synthetic vernix caseosa has been patented but is not available commercially.

The skin of very premature infants is susceptible to physical trauma from adhesives, leads, tape, and other such products used on babies in neonatal intensive care units (NICUs). Even routine application of leads may cause skin denudation and ecchymoses. Macular depressions or outpouchings of skin, associated with loss of dermal elastic tissue, are a recently recognized entity in these infants. This condition has been termed anetoderma of prematurity. Atrophic-appearing areas may have a "cigarette paper" feel and may appear hyperpigmented (Figure 2).⁴ Anetoderma is most common on the trunk and extremities in areas that correspond with placement of monitoring leads, although it is not always associated with specific traumas. The lesions are scar-like and may resolve with time, though the natural history is unknown.

To decrease incidence of anetoderma of prematurity and other trauma to the skin, investigators have evaluated which methods of monitoring and handling are least injurious to the neonate's fragile skin. One study examined the effects of plastic tape, pectin barrier, and hydrophilic gel adhesives applied on neonatal skin for a 24-hour period. These adhesives are all commonly used in NICUs for securing vascular lines and endotracheal tubes and monitor leads. Researchers relied on TEWL, colorimetric measurements (to objectively measure erythema), and visual inspection to examine disruption of barrier function 30 minutes, 24 hours, and 48 hours after the three different adhesives were removed.⁵ Acrylic (plastic) adhesive tape and pectin barrier removal resulted in significant increases in TEWL and abnormalities on visual inspection and by colorimetric scores. Hydrophilic gel adhesives were clearly less traumatic to the epidermal barrier than the other two adhesives. The gel adhesive was not as adherent as other adhesives to skin on infants with higher TEWL at baseline (birth weight less than 1,000 g), however. In fact, seven of 30 gel adhesives did not stay in place the entire 24 hours. Although no adhesive is ideal, hydrophilic gel has minimal effects on skin barrier function.

Care of the umbilical cord. Recommendations on caring for the umbilical cord have varied historically and are inconsistent. Care options include triple dye (a bacteriocidal agent), isopropyl alcohol, povidone-iodine, antibiotic ointments, and soap and water. For decades, physicians have recommended using alcohol swabs to cleanse the umbilical cord in the belief that this practice decreases rates of infection and shortens cord-separation time. No studies have proven the benefits of this method, however. The use of alcohol swabs or triple dye has been shown to decrease early colonization with Staphylococcus aureus, but colonization rates do not correlate with rates of infection.⁶

Recent reports question the utility of caring for the cord with isopropyl alcohol. In a study of 148 infants comparing daily alcohol application with wiping the umbilical area with sterile water, cord separation time was two to three days longer in the alcohol-treated group. Rates of microbial colonization differed in the two groups, but neither group had any umbilical infections.⁷ A larger study that compared alcohol treatment of the umbilicus with natural air drying found no difference in infection rates.⁸ In addition, several studies have shown that the cord separates sooner when it is left to dry naturally. The mean time of cord separation in healthy newborns is eight days with no treatment and 10 days with alcohol treatment. Cord separation time ranges from one to 24 days when the cord is allowed to dry naturally and two to 49 days when the cord is treated with alcohol.⁸

Parents should avoid using povidone-iodine swabs for cord care. Topical exposure to iodine in the perinatal or neonatal period has been associated with elevated plasma and urine iodine, resulting in transient hypothyroxinemia and hypothyroidism. In one study of very low birth-weight infants, the urine of those exposed to antiseptics containing topical iodine contained up to 50 times as much iodine as the urine of nonexposed infants.⁹ Within two weeks, one quarter of the 36 infants exposed to iodine had elevated serum thyrotropin levels compared with none of the controls. Because disturbances in thyroid function correlated positively with urinary iodine excretion, reflecting iodine absorption, investigators concluded that topical iodine-containing antiseptics may cause hypothyroidism during a critical period of neurologic development.

The practice of cost-efficient medicine calls for assessment of the financial effects of any proposed change in practice. Clearly, the use of alcohol swabs in newborn cord care is not a major financial burden. For normal vaginal births, the cost of alcohol treatment in a 48-hour hospital stay is approximately $0.52 per infant.⁷ Nonetheless, elimination of this practice in a hospital with an average of 2,500 births per year would save the institution $1,300 a year. When it comes to caring for umbilical cords, no treatment may be the best treatment.

General guidelines for newborn skin care

In caring for their newborn's skin, parents are most likely to need guidance in three areas: bathing, diaper choice, and keeping the infant's skin moisturized.

Bathing newborns serves a variety of functions. Bathing washes away urine and stool residue, bonds the infant and caretaker through tactile stimulation, and, possibly, decreases microbial colonization. Bathing may also place the newborn at risk for hypothermia, exposure to irritating substances, or absorption of potentially toxic compounds, however.

Many parents turn to their physician for advice about what soap to use in bathing their baby. Unfortunately, few studies are available to help a pediatrician make an informed decision. Most skin cleansing products are soaps or synthetic detergents. All are at least mildly irritating and drying to the skin. Skin pH serves as a natural form of antimicrobial protection. At birth, the mean skin pH is 6.4. Within a few days, the skin pH has decreased to 4.9; a skin pH of less than 5.0 discourages development of bacteria. Soaps, which are alkaline, may delay development of the "acid mantle," potentially increasing the risk of neonatal infection.⁸

Most parents choose a "baby" soap in the belief that it is gentler than other soaps. In general, this is true. Some commercial baby soaps have additives and perfumes that may be irritating to young skin, however. It is best to use a soap that is hypoallergenic and has few perfumes.¹⁰ Rinsing the soap off completely with clean water helps decrease any skin irritation. In general, parents should be encouraged not to bathe the infant more often than every other day. Table 1 lists some general principles for bathing the baby.

TABLE 1
Bathing the baby

Keep bathing regimens simple and gentle

Encourage bathing no more often than every other day

Soap is not necessary; if used, avoid harsh soaps

Rinse adequately to minimize skin irritation

Choosing a diaper. Diaper dermatitis exists only in regions of the world where infants wear diapers. In this country, parents are likely to reject the idea of keeping diapers off their baby. What diaper parents choose can affect how likely the baby is to develop diaper dermatitis, however. Although some parents prefer natural cloth diapers, hoping they will be better for the infant's skin or the environment, many studies show that disposable diapers decrease the incidence of diaper dermatitis.¹¹ Diaper technology has evolved during the past two decades, and central absorbent areas are now composed of absorbent gel polymers. These gels are highly efficient, as anyone who has seen a child wearing a disposable diaper step out of a wading pool can testify. The outer coverings of diapers vary in how well they keep urine and stool within, while allowing for vapor exchange. A new diaper design transfers petrolatum and zinc oxide to the diaper area (Rash Guard from Proctor & Gamble); an earlier model of this diaper containing only petrolatum was shown to decrease incidence of dermatitis.¹² The petrolatum/ zinc oxide diapers cost more than others, however. Other new diapers (from Kimberly-Clark) use Gor-Tex to create microchannels that efficiently "wick away" urine from the skin, allowing an exchange of air between the exterior of the diaper and the skin, without permitting the urine to escape.

Despite the availability of these products, incidence of diaper dermatitis is very high. Some estimate that at any time 12% to 15% of infants in the US have a rash that warrants parental intervention (Figure 3). Many factors cause diaper dermatitis. Irritant dermatitis, contact allergy, and candidal and bacterial infection may all contribute.¹³ Factors that are believed to influence development of dermatitis include fecal enzymes, urine pH (which may influence stool enzyme activity), stool frequency, and stool consistency. The influence of diet is not well understood. Diaper dermatitis with candidal infection may respond to a variety of topical antifungals, such as nystatin, clotrimazole, and econazole.

Infectious dermatitis of the diaper area usually appears in the folds of skin where moisture and warmth allow yeast or bacteria to proliferate, most commonly Candida and staphylococci (Figure 4). Diaper rashes that are unusual in appearance or unresponsive to standard therapy may suggest more significant processes, including psoriasis and histiocytosis (Figure 5). Table 2 suggests an approach to treatment of diaper dermatitis.

TABLE 2
Treating diaper dermatitis

Mild irritant dermatitis

Change diapers frequently

Avoid harsh or irritating soaps or other cleaning agents

Use a barrier cream with each diaper change (such as Triple Paste, zinc oxide, Desitin, A and D ointment)

Moderate to severe dermatitis

Follow measures for mild irritant dermatitis

Apply hydrocortisone 1% cream or ointment twice a day. May be applied with each change for severe cases, but for no longer than five to seven days

Use antiyeast topical agent (such as nystatin or econazole). May use with each diaper change when rash is severe

Chronic unresponsive diaper rash

Assess for oral thrush and treat if present

Consider applying topical antibiotic ointment (such as mupirocin) when signs of bacterial infection are present. (It is best to avoid these products because of the risk of contact allergy.) May treat diffuse pustules and bullae with oral antistaphylococcal antibiotics

Moisturizing the skin. Term babies are born with a protective layer, vernix caseosa. Leaving this hydrophobic, bactericidal vernix layer intact appears to be beneficial to the newborn skin. Once the layer is removed, or has worn off, newborn skin dries more readily, especially when the baby is bathed frequently and with necessary diaper-area cleanings. The dry and scaling skin of infants born beyond term may become worse with frequent baths as well. Parents may apply ointments or lotions that are hypoallergenic and contain no perfumes immediately after bathing and apply them again several times a day if needed.¹⁴ The accompanying parent guide can help parents care for their baby's skin.

Common skin conditions

Most common skin conditions in the newborn are benign. Although they generally resolve sponateously with time, it's important to identify these entities so you can reassure parents about their transience.

Seborrheic dermatitis. Flaking and dryness of the infant scalp (cradle cap) is most often a form of seborrheic dermatitis that is most common in the first few months of life. The fine scaling on the vertex may be greasy and yellow and sometimes erythematous. Seborrheic dermatitis is an inflammatory eczematous dermatitis whose cause is unknown, though its pathogenesis is associated with Pityrosporum ovale colonization or infection (Figure 6). Cradle cap usually responds promptly to topical treatment. An antiseborrheal shampoo containing selenium or zinc may help though it can sting the infant's eyes. Mineral oil applied once a day is a simple and effective alternative for mild disease. Combing the oil through the hair until it has softened the dry scales, then rinsing it out completely, will usually improve the cradle cap within a few days. If the scaling is severe or the scalp is severely erythematous, topical 1% hydrocortisone cream or ointment applied several times daily for up to a week will cause marked improvement. Treatment with topical ketoconazole 2% has also shown benefit.

Mongolian spots (dermal melanocytosis) are flat, deep brown to blue-black macular lesions that are often poorly circumscribed (Figure 7). Usually located over the buttocks and lumbosacral area, these lesions also appear on lower limbs, the shoulder, and flanks. The lesions result from collections of melanocytes located deep in the dermis that most likely failed to migrate normally from the neural crest to the dermis. Mongolian spots are very common, developing in more than 90% of blacks and Native Americans, 81% of Asians, 70% of Hispanics, and 9.6% of Caucasians. The lesions fade gradually over time and usually disappear by late childhood.

Nevus simplex lesions, which are also called salmon patches, angel kisses, stork bites, and telangiectatic nevi, are the most common vascular lesions of infancy (Figure 8). They are present in 30% to 40% of all newborns. The lesions are flat and pink and appear over the nape of the neck, eyelids, glabella, forehead, or nasolabial areas. Unlike hemangiomas, nevus simplex lesions are dilated dermal capillaries without a proliferative phase of growth. In some infants and children, nevus simplex lesions located over the neck may be associated with a dermatitis overlying the stain. Stains at the back of the neck often persist into adulthood, unlike lesions located in other areas such as the eyelids and forehead, which almost all fade slowly during the first few years of life.

Milia appear in almost half of newborns and result when keratin and sebaceous material are transiently trapped in the pilosebaceous apparatus. Milia are most common on the face, especially the nasal area. The lesions are small (usually less than 3 mm) papules that are white or yellow. Epstein pearls and Bohn nodules have a similar pathophysiologic basis. Epstein pearls develop on the hard palate and Bohn nodules on the gums. All these lesions resolve spontaneously over weeks to months.

Miliaria, which should not be confused with milia, is a common rash that is caused by sweat retention within the eccrine ducts. Newborns get two major types of miliaria: miliaria rubra (also known as prickly heat or heat rash) and miliaria crystallina (sudamina). Tiny superficial vesicles without surrounding erythema characterize miliaria crystallina. Miliaria rubra features very small (1 to 3 mm) erythematous vesicles or papulopustules. To prevent and "treat" this condition, parents should avoid placing their infants in excessively hot and humid conditions. Babies should be dressed in lightweight clothing, bathed in cool water, and kept in a comfortable temperature. Many infants develop miliaria in the first few weeks of life, but as the eccrine sweat glands mature, it becomes less common.

Sucking blisters, caused by in utero sucking, are often noted at birth. These bullae are usually on the hands, arms, feet, and lips. It is important to make sure that no new blisters form over areas of friction, which could be a sign of epidermolysis bullosa, an inherited disorder that can result in mutilation and is potentially lethal.

Transient neonatal pustular melanosis occurs in 2% to 5% of black infants and in 0.6% of Caucasian infants. The lesions are superficial vesiculopustules located over the face, neck, thorax, and, occasionally, extremities. Lesions are always present at birth, easily rupture, and create hyperpigmented spots that resolve spontaneously over days to weeks. The cause of transient neonatal pustular melanosis is unknown, and Gram stains show no organisms. Wright stain reveals keratinous debris, neutrophils, and, occasionally, eosinophils.

Cutis marmorata is a reticulated, bluish pattern of mottling of the skin that is a normal physiologic response to chilling (Figure 9). The pattern is created by dilatation of capillaries and small venules. Cutis marmorata may be noted within the first hours of life and can occur until the infant is several months old. The mottling usually disappears when the child is warmed.

Erythema toxicum, which arises in more than one third of newborns, is the most common cause of pustules in this age group. Its cause is unknown. In 75% of cases the lesions develop between 24 and 48 hours of life. It is not unusual for erythema toxicum to begin when the infant is a few days old, however. Lesions are small white or flesh-colored papules or pustules on an erythematous base (Figure 10). Microscopic examination of a scrape of the lesions reveals clusters of eosinophils. Erythema toxicum typically resolves within two weeks, and infants with the condition are otherwise healthy.

Sebaceous hyperplasia results from maternal androgenic influence and from testosterone synthesis in the fetal adrenal gland and fetal testis. Sebaceous hyperplasia is characterized by multiple white-yellowish papules that are regularly spaced over the nose, cheeks, and, occasionally, lips (Figure 11). Nearly one half of term neonates have sebaceous hyperplasia; it is less common in premature infants. It can be differentiated from milia, which are more discrete and whiter in color. Sebaceous hyperplasia resolves spontaneously when hormone levels decrease and the sebaceous glands regress to their immature childhood state.

Neonatal acne, like sebaceous hyperplasia, is hormonally induced. It is a common papulopustular eruption that can be seen at birth or within the first few weeks of life (Figure 12). Some observers recently proposed that the condition is pathophysiologically distinct from acne vulgaris, and suggest calling it "neonatal cephalic pustulosis." The condition may be an inflammatory reaction to Pityrosporum (Malassezia) species, namely M furfur or M sympodialis. Unlike in classic acne, comedones are not a feature of this condition, nor is follicular accentuation. Neonatal acne generally resolves spontaneously. Rapid response to topical ketoconazole has been reported as well. In older infants with comedonal papules and pustules, a condition called infantile acne, topical benzoyl peroxide, erythromycin, or low-strength topical retinoids, such as tretinoin 0.25% cream, can be used. Table 3 summarizes common neonatal skin conditions that require no treatment.

TABLE 3
Common neonatal skin findings that require no intervention

Bohn nodules

Cutis marmorata

Epstein pearls

Erythema toxicum

Infantile acne/pustulosis

Milia

Miliaria crystallina

Mongolian spot (dermal melanocytosis)

Neonatal acne

Nevus simplex (salmon patch/angel's kiss/stork bites)

Sebaceous hyperplasia

Sucking blisters

Transient neonatal pustular melanosis

Help parents keep their cool

Parents often expect their child's pediatrician to give them advice on caring for their newborn's skin. They may require basic guidelines on bathing, moisturizing, and avoiding diaper rash. Parents also need to be aware that infants frequently develop transient lesions that require no treatment. Reassurance is usually all that is required.

REFERENCES

1. Holbrook KA: Structure and function of the developing human skin., in Goldsmith LA (ed): Physiology, Biochemistry and Molecular Biology of the Skin, ed 2. New York, NY, 1991, p 63

2. Kalia YN, Nomato LB, Lund CH, et al: Development of skin barrier function in premature infants. J Invest Dermatol 1998;111:320

3. Nopper AJ, Horii KA, Sookdeo-Drost S, et al: Topical ointment therapy benefits premature infants. J Pediatr 1996;128 (5, pt 1):660

4. Prizant TL, Lucky AW, Frieden IJ et al: Spontaneous atrophic patches in extremely premature infants. Arch Dermatol 1996;132:(6):671

5. Lund Ch, Nonato LB, Kuller JM, et al: Disruption of barrier function in neonatal skin associated with adhesive removal [comments]. J Pediatr 1997;131:367

6. Wang E, Elder D: Staphylococcus aureus colonization and infection after discharge from a term newborn nursery. Infection Control 1987;8:30

7. Medves JM, O'Brien BA: Cleaning solutions and bacterial colonizaton in promoting healing and early separation of the umbilical cord in healthy newborns. Can J Public Health 1997;88:380

8. Dore S, Buchan D, Coulas S, et al: Alcohol vs. natural drying for newborn cord care. J Obstet Gynecol Neonatal Nurs 1998;27(6):621

9. Ronchira-Oms C, Hernandez C, Jiminez N: Antiseptic cord care reduces bacterial colonization but delays cord detachment. Arch Dis Child Fetal Neonatal Ed 1994; 71(1):F70

10. Smerdely P, Lim A, Boyages SC, et al: Topical iodine-containing antiseptics and neonatal hypothyroidism in very low-birth weight infants. Lancet 1989; 2(8664):661

11. Schuman AJ: Disposable diapers? Definitely! Contemporary Pediatrics 1997;14(11):131

12. Odio MR, O'Connor RJ, Sarbaugh F, et al: Continuous topical administration of a petrolatum formulation by a novel disposable diaper. Dermatology 2000;200(3):232

13. Arnsmeier SL, Paller AS: Getting to the bottom of diaper dermatitis. Contemporary Pediatrics 1997;14(11):115

14. Garcia-Gonzalez E, Rivera-Rueda MA: Neonatal Dermatology: Skin Care Guidelines. Dermatology Nursing 1998;10(4);274, 279

DR. MENDENHALL is Attending Physician, Pediatrics and Adolescent Medicine, Children's Hospital and Health Center, and Children's Primary Care Medical Group, San Diego, CA.

DR. EICHENFIELD is Director, Pediatric and Adolescent Dermatology, and Associate Professor, Pediatrics and Medicine, Children's Hospital,San Diego and University of California, San Diego School of Medicine, San Diego, CA.

GUIDE FOR PARENTS
How to care for your newborn's skin

Your baby's skin is more than a covering. The skin is an important organ. It acts as a barrier against infection and injury and helps to regulate temperature and bodily fluids. Taking good care of your baby's skin is therefore an essential part of maintaining his or her good health.

To keep your baby's skin healthy, you need to follow some basic guidelines about bathing, moisturizing, and diapering.

Bathing the baby

Bathing has several functions. It washes away urine and stool residue, provides valuable physical closeness between baby and parents, and may decrease the possibility of infection. But bathing also increases the risk that the baby's temperature will fall lower than it should and exposes him to irritating substances. To emphasize the good aspects of bathing and avoid those that are bad, remember the following:

• Bathe the baby every other day. Daily baths are unnecessary and may dry out the skin

• Wash the genital area after a bowel movement; washing is not necessary after urination

• Choose a soap or other cleansing agent that is hypoallergenic and isn't perfumed (check the product label)

• Rinse the soap off thoroughly with clean water

Moisturizing the skin

It is essential to keep your baby's skin moist. If your newborn's skin is dry or peeling, you may apply an ointment or lotion all over her body. Use a product that is hypoallergenic and contains no perfume. Also apply the ointment or lotion in the genital area when you wash it after a bowel movement.

Avoiding diaper rash

The best way to prevent a rash in the genital area is to keep the baby's skin away from urine and feces, which irritate the skin. To do this, use superabsorbent disposable diapers and change them frequently. If the baby develops a rash, despite these precautions, use a barrier cream each time you change the diaper. Examples are creams containing zinc oxide, Triple Paste, Desitin, or A and D ointment. Be especially careful to avoid harsh or irritating soaps or other cleansing agents. If the rash persists for several days, consult the baby's doctor, who may suggest other measures.

Other skin problems

Don't be alarmed if your baby's skin does not remain uniformly spotless. Newborns often have discolorations or lesions of one kind or another. Most of the time these marks are harmless and will disappear by themselves with time. Your baby's doctor will know if an irregularity in your baby's skin requires treatment.

 

Lawrence Eichenfield, Anna Mendenhall. Back to basics: Caring for the newborn's skin. Contemporary Pediatrics 2000;8:98.