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NEWBORN AND INFANTILE CONDITIONS

Nevus sebaceus

The nevus sebaceus represents a congenital hamartoma of sebaceous elements. It is most common on the scalp. A round or oval, red to yellow, smooth plaque on the scalp at birth is characteristic (Fig.19.21). The face is the second most commonly affected site. At puberty, under hormonal influence, the plaque may become verrucous or studded with multiple papules, like a mulberry. Many appendageal neoplasms, both benign and malignant, may develop within the nevus sebaceous (see Ch.23). Syringocystadenoma papilliferum and basal cell carcinoma are the most common. Some nevus sebaceus are familial. A systematized variant of nevus sebaceus occurs and is analogous to the epidermal nevus syndrome. Internal abnormalities may be associated with this variant.

    The differential diagnosis of a congenital alopecic area in the scalp also includes the following.

Surgical excision at or before puberty is recommended because of the risk of malignancy.

Epidermal nevus

The epidermal nevus is a congenital hamartomatous collection of keratinocytes that form a raised, usually linear or sometimes whorled lesion (the latter following the lines of Blaschko). Linear, coalescent, tan or brown papules and plaques are seen and may occur on any part of the body (Fig.19.22). Onset is usually at birth or early in life.

    Keratolytics can lessen the roughness of some lesions, but they cannot remove the lesion. Small lesions may be removed surgically by excision, shaving, curettage, or electrocautery. CO₂ laser treatment may be successful, but substantial scarring may occur.

Figure 19.22  Epidermal nevus. (a) A linear, brown coalescence of papules running vertically along the nape. (b) A larger concentration of papules. (Courtesy of O. Dale Collins III, M.D., Ph.D.)

Figure 19.23  Epidermal nevus. (a) The epidermal nevus represents a localized hyperplasia of epidermal elements. It ranges greatly in size and, when large, may follow Blaschko lines, as shown here. The widely distributed type may be associated with systemic abnormalities of the musculoskeletal, ocular, and neurologic systems. (b) This young girl has diffuse hyperkeratotic and verrucous lesions with linear areas and midline demarcation. Epidermolytic hyperkeratosis would not show such respect for the midline.

Epidermal nevus, systematized

Epidermal nevi may occur in a diffuse, systematized fashion. Systemic abnormalities are very common and may affect the musculoskeletal, ocular, and neurologic systems.

    Rarely, vitamin D-resistant rickets and precocious puberty have been associated. In both of these cases, it has been postulated that the nevus releases a factor that is causative. For example, after surgical debulking, the phosphate level of a patient with rickets and poorly controlled hypophosphatemia was much more easily controlled.

    Widespread verrucous lesions in an infant are characteristic. These may be whorled or linear, distributed locally, segmentally, unilaterally, or diffusely (Fig.19.23).

    A multidisciplinary approach with an emphasis on finding any systemic abnormalities should be performed. No reliable therapy exists for the skin changes other than simple excision or other destructive therapies of small lesions (see earlier). Tretinoin daily, combined with 5% 5-fluorouracil twice a day, produced dramatic clearing in one case.

Inflammatory linear verrucous epidermal nevus

A linear, inflamed, psoriasiform or verrucous lesion in a child (Fig.19.24) is the classic presentation for inflammatory linear verrucous epidermal nevus (ILVEN). These nevi may be present congenitally or develop in infancy or childhood. Most are present by 5 years of age, and the legs are most commonly affected. It appears that ILVEN is probably a variant of an epidermal nevus with psoriasiform features histologically. Only rarely are any systemic abnormalities associated.

Surgical excision of small lesions is curative. No topical therapy has proved consistently effective. Calcipotriol or other vitamin D3 derivatives, or potent topical steroids, have been used.

Persistent vitelline duct

A persistent vitelline duct connects the infant's umbilicus to the gastrointestinal tract.

    Intermittent discharge or bleeding should arouse suspicion (Fig.19.25). Surgery is needed.

Calcinosis cutis

White papules on the heels of a newborn representing calcinosis cutis
may occur after blood sampling using heel sticks (Fig.19.26). It is said to be related to repeated sampling but can occur after a single event. No treatment is needed.

Blueberry muffin baby

The ‘blueberry muffin' rash is defined as multiple dark bluish skin nodules in the infant, which histologically represent dermal (extramedullary) hematopoiesis. Infectious causes of this condition are conveniently summarized by the TORCH acronym for congenital infections: toxoplasmosis, other (syphilis, parvovirus, and other viral), rubella (the commonest cause), cytomegalovirus, and herpes simplex. Chronic prenatal anemia leading to blueberry muffin lesions in the neonate has been reported in association with severe hemolytic anemia such as congenital spherocytosis, rhesus hemolytic disease, and ABO incompatibility, or in anemia caused by twin-to-twin transfusion. Clinically, one sees discrete, red to purple macules and papules, 3–8 mm in diameter, in a newborn (Fig.19.27). Leukemia cutis and metastatic rhabdomyosarcoma or neuroblastoma have been reported to cause similar lesions.

    Treatment obviously depends on the cause.

Figure 19.24  Inflammatory linear verrucous epidermal nevus (ILVEN). An inflamed linear lesion on the leg of a female patient.

Figure 19.25 Persistent vitelline duct. A moist track is illustrated. The luminal surface is mucosal. Sometimes the condition is misdiagnosed as a pyogenic granuloma.

Shoulder dimples

Bilateral shoulder dimpling may occur and is an incidental finding (Fig.19.28).

Aplasia cutis congenita

Aplasia cutis congenita (ACC) is a condition where there is congenital absence of skin on the scalp. Often, in utero healing has occurred, and at birth, a thin membrane of a scar is the only manifestation.

    A congenital, circumscribed area of alopecia and scarring on the scalp is characteristic (Fig.19.29). Any site may be involved. Frieden has classified ACC into nine groups based on location, associated abnormalities, and inheritance. For example, ACC of the scalp associated with limb abnormalities may be inherited (autosomal dominant). Work-up should include an examination of the hair, nails, and teeth to exclude associated cutaneous abnormalities and epidermolysis bullosa, as congenital absence of skin may be the presenting sign of the latter. A history and physical examination by a pediatrician should try to exclude any internal abnormalities. Various trisomies (e.g. chromosomes 10 or 13) may also cause scalp defects. The presence of dense hair at the periphery (hair collar sign) should raise the possibility of a more significant defect (e.g. rudimentary meningocele). Adams–Oliver syndrome is the association of congenital ACC of the scalp with underlying skull defects and distal limb abnormalities.

Figure 19.26 Calcified nodule due to heel prick blood sampling. A solitary white papule on the heel is typical. In some cases, multiple lesions are seen.

Figure 19.27 ‘Blueberry muffin baby. These blue papulonodules represent dermal erythropoiesis. (Courtesy of Michael O. Murphy, M.D.)

    Most lesions of ACC are small, stable lesions and are mainly of cosmetic significance. The rare, larger, ulcerative lesion should be allowed to heal. Surgical repair may be performed later if needed. Rarely, large lesions may require grafting.

Figure 19.28  Bilateral shoulder dimples.

Subcutaneous fat necrosis

Multiple, deep, subcutaneous nodules, or a panniculitis appearing within the first few weeks of life, are characteristic (Fig.19.30). The skin may be red-purple or flesh-colored. The lesions are not tender. The newborn is usually full term. The distribution of lesions may be in areas of trauma (e.g. from forceps). Hypercalcemia may be associated. Signs and symptoms of hypercalcemia include irritability, poor feeding, and vomiting. Death has occurred from infection and cardiac arrest. Thrombocytopenia, hypoglycemia, and hyperlipidemia have also been associated. Usually, a history of obstetric trauma, meconium aspiration, neonatal asphyxia, hypothermia, or peripheral hypoxemia can be elicited. Fine-needle aspirate allowed for the diagnosis in one case, showing necrotic fat cells with refractile needle-shaped crystals.

    No treatment is needed, as the lesions remit spontaneously within weeks to months. The infant should be monitored for elevated calcium, especially if the disease is extensive. Treatment for hypercalcemia can include saline hydration, a low-calcium diet, furosemide, and glucocorticoid. For infants who fail to respond to standard measures, the use of oral biphosphonates, for example clodronate, has been reported to be very effective.

White/Cox: Diseases of the Skin, 2ed.(c) 2006, Elsevier Inc. All rights reserved.