Examine the skin of the newborn or infant carefully to identify both normal markings and potentially abnormal ones. The newborn's skin has a unique characteristic texture and appearance. The texture is soft and smooth because it is thinner than the skin of older children. Within the first 10 minutes after birth a normal newborn progresses from generalized cyanosis to pinkness. In lighter-skinned infants, an erythematous flush, giving the skin the appearance of a "boiled lobster," is common during the first 8 to 24 hours after which the normal pale pink coloring predominates.

Vasomotor changes in the dermis and subcutaneous tissue—a response to cooling or chronic exposure to radiant heat—can produce a lattice-like, bluish mottled appearance (cutis marmorata), particularly on the trunk, arms, and legs. This response to cold may last for months in normal infants. Acrocyanosis, a blue cast to the hands and feet when exposed to cold, is very common in newborns for the first few days and may recur throughout early infancy. Occasionally in newborns, a remarkable color change (harlequin dyschromia) appears with transient cyanosis of one half of the body or one extremity, presumably from 

temporary vascular instability.

The amount of melanin in the skin of newborns varies, affecting pigmentation. Black newborns may have a lighter skin color initially, except in the nail beds, genitalia, and ear folds which are dark at birth. A dark or bluish pigmentation over the buttocks and lower lumbar regions is common in newborns of African, Asian, and Mediterranean descent. These areas, called slate blue patches, result from pigmented cells in the deep layers of the skin; they become less noticeable with age and usually disappear during childhood. Document these pigmented areas to avoid later concern about bruising.

At birth, there is a fine, downy growth of hair called lanugo over the entire body, especially the shoulders and back. This hair is shed within the first few weeks. Lanugo is prominent in premature infants. Hair thickness on the head varies considerably among newborns and is not predictive of later hair growth. All of the original hair is shed within months and is replaced with a new crop, sometimes of a different color.

Inspect the newborn closely for a series of common skin conditions. At birth, a cheesy white material called vernix caseosa, composed of sebum and desquamated epithelial cells, covers the body. Some newborns have edema over their hands, feet, lower legs, pubis, and sacrum; this disappears within a few days. Superficial desquamation of the skin is often noticeable 24 to 36 hours after birth, particularly in postterm babies (>40 weeks gestation), and it can last for 7 to 10 days.

You should be able to identify four common dermatologic conditions in newborns—miliaria rubra, erythema toxicum, pustular melanosis, and milia. None of these is clinically significant.

Note any signs of trauma from the birth process and the use of forceps or suction; these signs disappear but should prompt a careful neurologic examination.

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