Cutaneous disorders of the newborn

Skin care of the newborn

The skin of the newborn is covered with a grayish-white, greasy material termed vernix caseosa . The vernix represents a physiologic protective covering derived partially from secretions of the sebaceous glands and in part as a decomposition product of the infant’s epidermis. Vernix contains protein, lipids, and water and provides water-binding free amino acids that facilitate the adaptation from amniotic fluid immersion in utero to the dry ambient postnatal state. Although its function is not completely understood, it may act as a natural protectant cream to “waterproof” the fetus in utero , where it is submerged in the amniotic fluid. Some studies suggest that vernix be left on as a protective coating for the newborn skin and that it be allowed to come off by itself with successive changes of clothing (generally within the first few weeks of life). It has been suggested that vernix-based topical creams may be effective in augmenting stratum corneum repair and maturation in infants and could play a role in the treatment of epidermal wounds.

The skin acts as a protective organ. Any break in its integrity therefore affords an opportunity for initiation of infection. The importance of skin care in the newborn is compounded by several factors:

• 1.

  The infant does not have protective skin flora at birth.

• 2.

  The infant has at least one and possibly two open surgical wounds (the umbilicus and circumcision site).

• 3.

  The infant is exposed to fomites and personnel that potentially harbor a variety of infectious agents.

Skin care should involve gentle cleansing with a nontoxic, nonabrasive neutral material. During the 1950s, the use of hexachlorophene-containing compounds became routine for the skin care of newborns as prophylaxis against Staphylococcus aureus infection. In 1971 and 1972, however, the use of hexachlorophene preparations as skin cleansers for newborns was restricted because of studies demonstrating vacuolization in the central nervous system (CNS) of infants and laboratory animals after prolonged application of these preparations. At the minimum, neonatal skin care should include gentle removal of blood from the face and head, and meconium from the perianal area, by gentle rinsing with water. Ideally, vernix caseosa should be removed from the face only, allowing the remaining vernix to come off by itself. However, the common standard of care is for gentle drying and wiping of the newborn’s entire skin surface, which is most desirable from a thermoregulatory standpoint. Recommendations for “first bathing” of the newborn suggest timing it according to local culture, performing it only after the newborn is physiologically stable and able to appropriately thermoregulate, considering the use of water alone or water and an appropriately formulated pH neutral (or acidic) liquid cleanser such as a synthetic detergent (syndet) or liquid baby cleanser, and considering the use of gloves by healthcare workers if performing the initial bath.

There is no single method of umbilical-cord care that has been proven to limit bacterial colonization and disease, and cord care practices are quite variable in relation to cultural beliefs and healthcare disparities. Several methods have been reported, including local application of isopropyl alcohol, triple dye (an aqueous solution of brilliant green, proflavine, and gentian violet), and antimicrobial agents such as bacitracin or silver sulfadiazine cream. The routine use of povidone-iodine should be discouraged, given the risk of iodine absorption and transient hypothyroxinemia or hypothyroidism. A safer alternative is a chlorhexidine-containing product. A recent clinical review suggests consideration of application of antimicrobial agents for infants born at home or otherwise outside of birthing centers or hospitals in resource-limited settings but highlights that their use in high-resource countries or the setting of in-hospital delivery has not been found to provide clear benefit.

Cutis marmorata

Cutis marmorata is a normal reticulated bluish mottling of the skin seen on the trunk and extremities of infants and young children ( Fig. 2.1 ). This phenomenon, a physiologic response to chilling with resultant dilation of capillaries and small venules, usually disappears as the infant is rewarmed. Although a tendency for cutis marmorata may persist for several weeks or months, this disorder bears no medical significance and treatment generally is unnecessary. In some children cutis marmorata may tend to recur until early childhood, and in patients with Down syndrome, trisomy 18, and Cornelia de Lange syndrome, this reticulated marbling pattern may be persistent. When the changes are persistent (even with rewarming) and are deep violaceous in color, cutis marmorata telangiectatica congenita ( Fig. 2.2 ; see also Chapter 12 ) should be considered. In some infants a white negative pattern of cutis marmorata (cutis marmorata alba) may be created by a transient hypertonia of the deep vasculature. Cutis marmorata alba is also a transitory disorder and appears to have no clinical significance.

Harlequin color change

Harlequin color change, a form of vascular autonomic dysregulation not to be confused with harlequin ichthyosis (see Chapter 5 ), is occasionally observed in full-term infants but classically described in premature infants. It occurs when the infant is lying on his or her side and consists of reddening of one-half of the body with simultaneous blanching of the other half. Attacks develop suddenly and may persist for 30 seconds to 20 minutes. The side that lies uppermost is paler, and a clear line of demarcation runs along the midline of the body. At times, this line of demarcation may be incomplete; when attacks are mild, areas of the face and genitalia may not be involved.

This phenomenon appears to be related to immaturity of hypothalamic centers that control the tone of peripheral blood vessels and has been observed in infants with severe intracranial injury as well as in infants who appear to be otherwise perfectly normal. Some medications, including anesthetics and prostaglandin E, may exacerbate the condition. Although the peak frequency of attacks of harlequin color change generally occurs between the second and fifth days of life, attacks may occur anywhere from the first few hours to as late as the second or the third week of life.

Infantile transient smooth muscle contraction of the skin

Believed to be a primitive reflex or autonomic phenomenon, infantile transient smooth muscle contraction of the skin refers to a transient rippling of the skin of otherwise-healthy infants, often triggered by cold or blowing air exposure. In a series of nine full-term newborns with this phenomenon, the authors noted several asymptomatic episodes occurring daily for brief periods (usually <1 minute), with completely normal–appearing skin in between episodes. Histologic examination was unremarkable in the skin biopsy specimens from three patients, and the episodes spontaneously resolved over 18 to 24 months. This condition appears to be related to transient arrector pili smooth muscle contraction, without features to suggest smooth muscle hamartoma.

Bronze baby syndrome

Bronze baby syndrome (BBS) is a term used to describe infants who develop a grayish-brown discoloration of the skin, serum, and urine while undergoing phototherapy for hyperbilirubinemia. Although the exact source of the pigment causing the discoloration is not clear, the syndrome usually begins 1 to 7 days after the initiation of phototherapy, resolves gradually over a period of several weeks after phototherapy is discontinued, and appears to be related to a combination of photoisomers of bilirubin or biliverdin or a photoproduct of copper-porphyrin metabolism. Infants who develop BBS usually have modified liver function, particularly cholestasis, of various origins. Although very few babies with cholestasis develop BBS during phototherapy, those who do should be investigated for underlying liver disease. The disorder should be differentiated from neonatal jaundice, cyanosis associated with neonatal pulmonary disorders or congenital heart disease, an unusual progressive hyperpigmentation (universal-acquired melanosis, or “carbon baby” syndrome), and chloramphenicol intoxication (“gray baby” syndrome). Although early recognition of BBS suggests further evaluation for associated disorders, it does not appear to be a contraindication to ongoing phototherapy for hyperbilirubinemia. A distinctive purpuric eruption on exposed skin has also been described in newborns receiving phototherapy and is possibly related to a transient increase in circulating porphyrins. This condition, however, is unlikely to be confused with BBS.

Sclerema neonatorum

Sclerema neonatorum is a diffuse, rapidly spreading, wax-like hardening of the skin and subcutaneous tissue that occurs in premature or debilitated infants during the first few weeks of life and may rarely present after several months of life. The disorder, usually associated with a serious underlying condition such as sepsis or other infection, congenital heart disease, respiratory distress, intracranial hemorrhage, diarrhea, or dehydration, is characterized by a diffuse nonpitting woody induration of the involved tissues. The process is symmetric, usually starting on the legs and buttocks, and may progress to involve all areas except the palms, soles, and genitalia. As the disorder spreads, the skin becomes cold, yellowish-white, mottled, stony hard, and cadaver-like. The limbs become immobile, and the face acquires a fixed mask-like expression. Infants with this disorder become sluggish, feed poorly, show clinical signs of shock, and, in a large percentage of cases, die.

Although the cause of this disorder is unknown, it appears to represent a nonspecific sign of severe illness rather than a primary disease. Infants with this disorder are characteristically small or premature, debilitated, weak, cyanotic, and lethargic. In 25% of cases the mothers are ill at the time of delivery. Exposure to cold, hypothermia, peripheral chilling with vascular collapse, and an increase in the ratio of saturated to unsaturated fatty acids in the triglyceride fraction of the subcutaneous tissue (because of a defect in fatty acid mobilization) have been hypothesized as possible causes for this disorder but lack confirmation.

The histopathologic findings of sclerema neonatorum consist of edema and thickening of the connective tissue bands around the fat lobules. Although necrosis and crystallization of the subcutaneous tissue have been described, these findings are more characteristically seen in lesions of SCFN.

The prognosis of infants with sclerema neonatorum is poor, and mortality occurs in 50% to 75% of affected infants. In a series of 51 infants with sclerema neonatorum in a special-care nursery within a Bangladeshi hospital, the fatality rate was 98%. In infants who survive, the cutaneous findings resolve without residual sequelae. There is no specific therapy, although steroids and exchange transfusion have been used.

Subcutaneous fat necrosis

Subcutaneous fat necrosis (SCFN) is a benign, self-limited disease that affects apparently healthy, full-term newborns and young infants. It is characterized by sharply circumscribed, indurated, and nodular areas of fat necrosis ( Fig. 2.8 ). The cause of this disorder remains unknown but appears to be related to perinatal trauma, asphyxia, hypothermia, and, in some instances, hypercalcemia. ^, Although the mechanism of hypercalcemia in SCFN is not known, it has been attributed to aberrations in vitamin D or parathyroid homeostasis. Birth asphyxia and meconium aspiration seem to be commonly associated. In one large series, 10 of 11 infants with SCFN had been delivered via emergency cesarean section for fetal distress, and 9 of the 11 had meconium staining of the amniotic fluid. The relationship among SCFN, maternal diabetes, and cesarean section, if any, is unclear. SCFN after ice-bag application for treatment of supraventricular tachycardia has been reported, and it has also been observed after selective head or generalized cooling for hypoxic-ischemic encephalopathy. ^, In a review of neonates with hypoxic-ischemic encephalopathy in Switzerland, 2.8% of all cooled neonates developed SCFN, which occurred independently of the cooling method used and the number of temperature measurements outside the target temperature range.

The onset of SCFN is generally during the first few days to weeks of life. Lesions appear as single or multiple localized, sharply circumscribed, usually painless areas of induration. Occasionally the affected areas may be tender, and infants may be uncomfortable and cry vigorously when they are handled. Lesions vary from small erythematous, indurated nodules to large plaques, and sites of predilection include the cheeks, back, buttocks, arms, and thighs ( Fig. 2.9 ). Many lesions have an uneven lobulated surface with an elevated margin separating it from the surrounding normal tissue. Histologic examination of skin biopsy tissue reveals larger-than-usual fat lobules and an extensive inflammatory infiltrate, needle-shaped clefts within fat cells, necrosis, and calcification. Fine-needle aspiration biopsy has been reported as a useful and less invasive method for diagnosis. Magnetic resonance imaging (MRI), although rarely performed, reveals decreased T1 and increased T2 signal intensity in affected areas.

The prognosis for SCFN is excellent. Although lesions may develop extensive deposits of calcium, which may liquefy, drain, and heal with scarring, most areas undergo spontaneous resolution within several weeks to months. Hypercalcemia is an association observed in up to 56% to 63% of infants in larger series, ^, and infants with this finding may require low calcium intake, restriction of vitamin D, and/or systemic corticosteroid therapy. Etidronate therapy has been reported for treatment of recalcitrant SCFN-associated hypercalcemia. ^, Infants should be monitored for several months after delivery, because the onset of hypercalcemia can be delayed. ^, Other rare systemic complications may include thrombocytopenia, hypoglycemia, and hypertriglyceridemia, all of which tend to be mild or self-limited.

Miliaria

Differentiation of the epidermis and its appendages, particularly in the premature infant, is often incomplete at birth. As a result of this immaturity, a high incidence of sweat-retention phenomena may be seen in the newborn. Miliaria, a common neonatal dermatosis caused by sweat retention, is characterized by a vesicular eruption with subsequent maceration and obstruction of the eccrine ducts. The pathophysiologic events that lead to this disorder are keratinous plugging of eccrine ducts and the escape of eccrine sweat into the skin below the level of obstruction (see Chapter 8 ).

Virtually all infants develop miliaria under appropriate conditions. There are two principal forms of this disorder:

• 1.

  Miliaria crystallina (sudamina), which consists of clear superficial pinpoint vesicles without an inflammatory areola ( Fig. 2.10 )

  

• 2.

  Miliaria rubra (prickly heat), representing a deeper level of sweat gland obstruction and characterized by small discrete erythematous papules, vesicles, or papulovesicles ( Fig. 2.11 )

  

The incidence of miliaria is greatest in the first few weeks of life because of the relative immaturity of the eccrine ducts, which favors poral closure and sweat retention. A pustular form of miliaria rubra has been observed in association with pseudohypoaldosteronism during salt-losing crises.

Therapy for miliaria is directed toward avoidance of excessive heat and humidity. Lightweight cotton clothing, cool baths, and air conditioning are helpful in the management and prevention of this disorder. Avoidance of emollient overapplication (e.g., in infants with atopic dermatitis) should also be recommended, especially in warm, humid climates or in the winter when infants are bundled under heavy clothing.

Milia

Milia, small retention cysts, commonly occur on the face of newborns. Seen in 40% to 50% of infants, they result from retention of keratin within the dermis. They appear as tiny 1- to 2-mm pearly white or yellow papules. Particularly prominent on the cheeks, nose, chin, and forehead, they may be few or numerous ( Fig. 2.12 ) and are often grouped, in which case they have been termed milia en plaque ( Fig. 2.13 ). Lesions may occasionally occur on the upper trunk, limbs, penis, or mucous membranes. Although milia of the newborn may persist into the second or third month, they usually disappear spontaneously during the first 3 or 4 weeks of life and accordingly require no therapy. Milia en plaque may occur in a congenital fashion, although they most often occur outside the newborn period, where they may be secondary to skin injury (e.g., abrasions) or blistering disorders. Persistent milia in an unusual or widespread distribution, particularly when seen in association with other defects, may be a manifestation of hereditary trichodysplasia (Marie-Unna hypotrichosis), dystrophic forms of epidermolysis bullosa, Bazex or Rombo syndromes, or type I oral-facial-digital syndrome.

Bohn nodules and Epstein pearls

Discrete, 2- to 3-mm round, pearly white or yellow, freely movable elevations at the gum margins or midline of the hard palate (termed Bohn nodules and Epstein pearls , respectively) are seen in up to 85% of newborns. Clinically and histologically the counterpart of facial milia, they disappear spontaneously, usually within a few weeks of life, and require no therapy.

Sebaceous gland hyperplasia

Sebaceous gland hyperplasia represents a physiologic phenomenon of the newborn manifested as multiple, yellow to flesh-colored tiny papules that occur on the nose, cheeks, and upper lips of full-term infants ( Fig. 2.14 ). A manifestation of maternal androgen stimulation, these papules represent a temporary disorder that resolves spontaneously, generally within the first few weeks of life.

Acne neonatorum

Occasionally infants develop a facial eruption that resembles acne vulgaris as seen in adolescents ( Fig. 2.15 ). Clinical examination typically reveals erythematous papules, pustules, and occasionally comedones (although the latter are more common in infantile acne; see Chapter 8 ). Although the cause of this disorder is not clearly defined, it appears to develop as a result of hormonal stimulation of sebaceous glands that have not yet involuted to their childhood state of immaturity. In mild cases of acne neonatorum, therapy is often unnecessary; daily cleansing with soap and water may be all that is required. Occasionally, benzoyl peroxide, a topical retinoid, or topical antibiotics may be helpful (see Chapter 8 ). Unusually severe or recalcitrant cases of acne neonatorum warrant investigation for underlying androgen excess.

A facial acneiform eruption in infants has been associated with the saprophytic Malassezia species and has been termed neonatal cephalic pustulosis (see Chapter 8 ). Lesions consist of pinpoint papules, papulopustules, or larger pustules, and they are located on the cheeks, chin, and forehead ( Fig. 2.16 ). A correlation may exist between the clinical severity of lesions and the colonization with this fungal saprophyte. ^, In these infants, topical antifungal agents may lead to more rapid resolution of lesions.

Erythema toxicum neonatorum

Erythema toxicum neonatorum (ETN), also known as toxic erythema of the newborn, is an idiopathic, asymptomatic, benign, self-limiting, cutaneous eruption in full-term newborns. Lesions consist of erythematous macules, papules, and pustules ( Fig. 2.17 ), or a combination of these, and may occur anywhere on the body, especially the forehead, face, trunk, and extremities. The fact that these lesions (which histologically reveal follicular-centered eosinophils) often tend to spare the palms and soles may be explained by the absence of pilosebaceous follicles in these areas.

ETN often initially appears as a blotchy, macular erythema that then develops firm, 1- to 3-mm, pale yellow or white papules and pustules. The erythematous macules are irregular or splotchy in appearance, varying from a few millimeters to several centimeters in diameter. They may be seen in sharp contrast to the surrounding unaffected skin, may blend into a surrounding erythema, or may progress to a confluent eruption.

Although ETN appears most commonly during the first 3 to 4 days of life, it has been seen at birth and may be noted as late as 10 days of age. Exacerbations and remissions may occur during the first 2 weeks of life, and the duration of individual lesions varies from a few hours to several days. The cause of ETN remains obscure. One study suggested that it represents an immune response to microbial colonization of the skin at the hair follicle. ETN incidence data are variable. Some authors report an incidence as low as 4.5%; others report incidences varying from 31% to 70% of newborns. Two large prospective series of skin findings in newborns (one in the United States and one in Turkey) found incidences of 7% and 13.1%, respectively. ^, In a prospective 1-year multicenter study of more than 2800 neonates in Brazil, the prevalence of ETN was 21.3%, and it was primarily noted in term infants. The incidence of ETN clearly appears to increase with increasing gestational age and birthweight of the infant. ^, No sexual or racial predisposition has been noted.

ETN is usually diagnosed clinically. Skin biopsy, which is rarely necessary, reveals a characteristic accumulation of eosinophils within the pilosebaceous apparatus. The diagnosis can be rapidly differentiated from other newborn pustular conditions by cytologic examination of a pustule smear that with Wright or Giemsa staining reveals a predominance of eosinophils. Affected infants may have a peripheral eosinophilia. Although the eosinophilic response has led some observers to attribute the cause of this disorder to a hypersensitivity reaction, specific allergens have never been implicated or confirmed.

Because erythema toxicum is a benign, self-limiting, asymptomatic disorder, no therapy is indicated. Occasionally, however, it may be confused with other pustular eruptions of the neonatal period, including transient neonatal pustular melanosis, milia, miliaria, and congenital infections such as candidiasis, herpes simplex, and bacterial processes. Of these, the congenital infections are the most important diagnostic considerations because of the implications for possible systemic involvement. Table 2.3 lists the differential diagnosis of the newborn with vesicles or pustules.

Eosinophilic pustular folliculitis

Eosinophilic pustular folliculitis (EPF) is an idiopathic dermatosis that occurs in both adults and children (particularly infants). When it occurs in neonates or young infants, it may be clinically confused with other vesiculopustular disorders. Lesions consist of follicular pustules, most commonly occurring on the scalp and the extremities ( Fig. 2.20 ). They tend to recur in crops, in a similar fashion to acropustulosis of infancy (see later), and some suggest that these conditions may be related. ^, As opposed to the adult form of EPF, the infancy-associated type does not reveal lesions grouped in an annular arrangement. EPF tends to present before 14 months of age in the majority of patients. Histologic evaluation reveals an eosinophilic, follicular, inflammatory infiltrate, and peripheral eosinophilia may be present. EPF of infancy appears to be distinct from classic (adult) and human immunodeficiency virus (HIV)–associated EPF, although an infant with HIV and EPF has been reported. Importantly, infantile EPF may occasionally be the presenting sign of hyperimmunoglobulinemia E syndrome (HIES) (see Chapter 3 ). Treatment for EPF is symptomatic, including topical corticosteroids and antihistamines, with eventual spontaneous resolution by 3 years of age in the majority of patients. Topical tacrolimus may be useful in patients who are unresponsive to topical corticosteroids.