Chapter 108. Normal Skin Changes

A 2-week-old infant is brought to the office for her first well-baby check. The parents noticed a rash on the face. You diagnose the white spots on the bridge of the nose as milia and neonatal acne on the cheeks. The parents are happy to hear that the neonatal acne and milia will go away without treatment (Figures 108-1 and 108-2).

• Rashes are common in newborns. Physicians will be consulted frequently as they are a common parental concern. Almost all newborn rashes are benign; however, a few are associated with more serious conditions. A newborn's skin shows a variety of changes during the first 2 months of life and most are self-limited. Physicians must be prepared to identify common rashes and advise parents.1
• Milia are inclusion cysts that appear as tiny white papules in the skin (Figure 108-1) or on the roof of the mouth.
• Neonatal acne is an acneiform eruption appearing as small red papules or whiteheads with surrounding erythema on the skin of newborns (Figure 108-2).
• A mongolian spot is a hereditary, congenital macule of bluish-black or bluish-gray pigment usually in the sacral area, back, and buttocks of infants (Figures 108-3 and 108-4).
• Erythema toxicum neonatorum (ETN) is a benign, self-limited skin eruption appearing as small yellow-white papules or vesicles with surrounding skin erythema (Figures 108-5 and 108-6).

• Milia are also called milk spots or oil seed.
• Neonatal acne is also called acne neonatorum.
• Mongolian spots are also known as mongolian blue spots, congenital dermal melanocytosis, and dermal melanocytosis.

• Approximately 40% of newborn infants in the United States develop milia.2 This condition is mainly associated with newborns carried to full term or near term.
• Neonatal acne occurs in up to 20% of the newborns. It typically consists of close comedones of the forehead, nose, and cheeks, although other locations are possible. It is most frequent in boys in the first week of life.3
• The prevalence of mongolian spots varies among different ethnic groups. They have been reported in approximately 96% of black infants, 90% of Native American infants, 81% to 90% of Asian infants, 46% to 70% of Hispanic infants, and 1% to 10% of white infants.2,4,5
• ETN occurs in 30% to 70% of full-term infants and in 5% of premature infants. The incidence rises with increasing gestational age and birth weight.6,7

• Milia are inclusion cysts that contain trapped keratinized stratum corneum surrounded by a dense lymphocytic infiltrate. Milia are caused by retention of keratin within the dermis. They may rarely be associated with other abnormalities in syndromes such as epidermolysis bullosa and the orofacial digital syndrome (type 1).2,8
• Maternal androgenic hormones that stimulate sebaceous glands likely cause neonatal acne.9
  • Hyperactivity of sebaceous glands, stimulated by neonatal androgens, has been implicated as the underlying pathogenic mechanism.
  • Histologic examination shows hyperplastic sebaceous glands with keratin-plugged orifices.
• The mongolian spot is a hereditary, congenital, developmental condition exclusively involving the skin. It results from entrapment of melanocytes in the dermis during their migration from the neural crest into the epidermis.
  • Mongolian spots are associated with cleft lip, spinal meningeal tumor, melanoma, and phakomatosis pigmentovascularis types 2 and 5.2,10
  • A few cases of extensive mongolian spots have been reported with inborn errors of metabolism, the most common being Hurler syndrome, followed by gangliosidosis type 1, Niemann-Pick disease, Hunter syndrome, and mannosidosis. In such cases, they are likely to persist rather than resolve.2,4
• The etiology of ETN is not known. ETN is thought to be an immune system reaction; the condition is associated with increased levels of immunologic and inflammatory mediators (e.g., interleukins 1 and 8, eotaxin).11
  • The eosinophilic infiltrate of ETN suggests an allergic-related or hypersensitivity-related etiology, but no allergens have been identified. Newborn skin appears to respond to any injury with an eosinophilic infiltrate.
  • Because ETN rarely is seen in premature infants, it is believed that mature newborn skin is required to produce this reaction pattern.

Clinical Features

• Milia are characterized as tiny, pearly white papules (see Figure 108-1) that are actually small inclusion cysts ranging from 1 to 2 mm in diameter. No visible opening is present.2
  • Milia usually appear after 4 to 5 days of life in full-term newborns. Manifestations of milia may be delayed from days to weeks in infants born before term.8,10
• Neonatal acne (Figure 108-2) includes comedones (i.e., whiteheads), papules, and pustules.
  • Papules and pustules are the most frequent types of lesions (72.7%), followed by comedones only (22.7%).2,9
• A mongolian spot (Figures 108-3 and 108-4) is a bluish-black macule or patch typically a few centimeters in diameter, although much larger lesions also can occur. Lesions may be solitary or numerous.
  • Generalized mongolian spots involving large areas covering the entire posterior or anterior trunk and the extremities have been reported.
  • Several variants exist including:2,4
    • Persistent mongolian spots—These are larger, have sharper margins, and persist for many years (Figure 108-4).
    • Aberrant mongolian spots involve unusual sites such as the face or extremities.
    • Persistent aberrant mongolian spots also are referred to as macular-type blue nevi.
• ETN commonly presents with a blotchy, evanescent, macular erythema (Figures 108-5 and 108-6).
  • The macules are irregular, blanchable, and vary in size.
  • In more severe cases (Figure 108-6), pale yellow or white wheals or papules on an erythematous base may follow. In approximately 10% of patients, 2- to 4-mm pustules develop.2,7
  • ETN occurs within the first 4 days of life in full-term infants, with the peak onset within the first 48 hours following birth. Rare cases have been reported at birth.
  • Delayed onset can rarely occur in full-term and preterm infants up to 14 days of age.
  • Infants with ETN otherwise are healthy and lack systemic symptoms.

Typical Distribution

• Milia are found on the forehead, nose, upper lip, cheeks, and scalp. They can, however, occur anywhere and may be present at birth or appear subsequently. The milia on the child in Figure 108-1 were present at birth.
• Neonatal acne occurs on the face with the cheeks being the most common site (81.8%) (Figure 108-2).2
• Mongolian spots most commonly involve the lumbosacral area (Figure 108-3), but the buttocks, flanks, and shoulders (Figure 108-4) may be affected with extensive lesions.
• ETN sites of predilection include the forehead, face, trunk, and proximal extremities, but lesions may occur anywhere, including the genitalia. Involvement of the mucous membranes and palms and soles rarely occurs (Figures 108-5 and 108-6).

Labs and Imaging

• No laboratory studies are required.
• In extensive mongolian spots involving the back, radiographic studies are needed to rule out a spinal meningeal tumor or anomaly.4
• ETN is often diagnosed clinically, based on history and physical examination, but a peripheral smear of intralesional contents can be done to confirm the diagnosis.2,7
  • A Tzanck smear or Gram stain shows inflammatory cells with greater than 90% eosinophils and variable numbers of neutrophils.
  • A complete blood count (CBC) also shows eosinophilia (up to 18%) in approximately 15% of patients. Eosinophilia may be more pronounced when the eruption shows a marked pustular component.

Other diagnoses that may be confused with milia, neonatal acne, and ETN include:

• Miliaria—Heat rash (prickly heat) with tiny papules that can be red (miliaria rubra) or clear (miliaria crystallina) or pustular (miliaria pustulosa) (Figure 108-7). Miliaria results from sweat retention caused by partial closure of eccrine structures. Both milia and miliaria result from immaturity of the skin structures, but they are clinically distinct entities.
• Neonatal pustular melanosis—This eruption, present at birth, consists of 2- to 4-mm nonerythematous vesicles filled with a milky fluid. This rash occurs in 5% of African American newborns and in less than 1% of white newborns, and fades in the first 3 to 4 weeks of life (see Chapter 110, Pustular Diseases of Childhood).

Mongolian spots may be confused with the following lesions also present at birth or shortly after:

• Congenital melanocytic nevi—These lesions are much less common (1% to 2% of newborns). They are of variable color from tan or brown to red or black, often within a single lesion and the pigment may fade off into surrounding skin. The borders are often irregular and the lesion can appear slightly raised over time (although a macular portion is usually found at the edges). Most congenital melanocytic nevi have a darker color and more discrete borders than mongolian spots. A biopsy is only needed if melanoma is suspected (see Chapter 163, Congenital Nevi).
• There are reports of Mongolian spots being confused for the bruising that occurs in child abuse. A good history and a clear knowledge of the pattern of mongolian spots should help to differentiate between these two entities.

ETN can also be confused with the following:

• Miliaria—See information above.
• Folliculitis—Primary lesion is a papule or pustule pierced by a central hair, although the hair may not always be visualized. Deeper lesions present as erythematous, often fluctuant, nodules. Folliculitis rarely occurs in the first few days of life when ETN is most commonly seen (see Chapter 117, Folliculitis).
• Chickenpox—The characteristic rash appears in crops of lesions beginning with red macules and passing through stages of papule, vesicle (on an erythematous base), pustule, and crust. Simultaneous presence of different stages of the rash is a hallmark. Infants are mostly born with adequate maternal antibodies to varicella, so that timing should differentiate between these two conditions (see Chapter 123, Chickenpox).
• Cutis marmorata (Figure 108-8) is reticulated mottled skin with symmetric involvement of the trunk and extremities produced by a vascular response to cold; the change resolves with heat. This entity can persist for weeks or months. No treatment is indicated.
• Harlequin color change affects 10% of full-term babies and occurs when the newborn lies on one side and erythema develops on one side of the body, while blanching is seen on the contralateral side. The color change fades after 30 seconds to 20 minutes and resolves with increased muscle activity or crying. It begins between the second to fifth days of life and lasts up to 3 weeks.12
• Neonatal lupus is a rare syndrome in which maternal autoantibodies are passively transferred to the baby producing well-demarcated, erythematous, scaling patches that are often annular, predominately on the scalp, neck or face (Figure 108-9). The condition is self-limited and resolves without scarring by 6 to 7 months of age. It is associated with congenital heart block. Treatment includes photoprotection; mild topical steroids may be helpful.

• Milia, neonatal acne, mongolian spots, and ETN are benign conditions and parents should be reassured that they resolve with time.
• Although acne treatment generally is not indicated, infants can be treated with a 2.5% benzoyl peroxide lotion if lesions are extensive and persist for several months.9

• Milia usually disappear within several weeks.
• Neonatal acne may come and go until the baby is between 4 and 6 months of age.
• Mongolian spots may persist for many years but usually disappear within 3 to 5 years and almost always by puberty.
• ETN usually lasts for several days but can change rapidly, with lesions appearing and disappearing in different areas over hours.

• Milia is a benign self-limiting rash that disappears within a few months without leaving any scars. No drug therapy is required and use of nonprescription rash medications is not recommended.
• Neonatal acne resolves on its own in weeks. Oils and lotions do not help and may actually aggravate the acne.
• Mongolian spots are likely to fade over time and may disappear by age 7 to 13 years.
• ETN will usually disappear within 2 weeks.

Patient Resources

• Milia—http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002343/.
• Neonatal acne—http://www.womenshealthcaretopics.com/baby_acne.htm.
• Mongolian spot—http://www.nlm.nih.gov/medlineplus/ency/article/001472.htm.
• ETN—http://www.nlm.nih.gov/medlineplus/ency/article/001458.htm.

Provider Resources

• http://www.adhb.govt.nz/newborn/teachingresources/dermatology/BenignLesions.htm.
• http://www.aafp.org/afp/2008/0101/p47.html.