Neonatal Dermatology
The session 'Neonatal dermatology' was presented by Nanette B Silverberg. Dermatology of the neonate can be extensive. Topics reviewed here include: neonatal pustules and vesicles, vertical transmission of cutaneous viral infections, as well as birthmarks. When a physician encounters a neonate with primary lesions consisting of pustules and vesicles the differential diagnoses include erythema toxicum, transient neonatal pustular melanosis, herpes simplex virus, scabies and candidiasis. If the patient is systemically ill, a consultation with pediatric dermatology is always ideal. Erythema toxicum occurs in the first 1–2 days and has eosinophils in the pustules. Transient neonatal pustular melanosis can be present at birth, may affect the palms and soles, and resolves with a collarette of scale and hyperpigmentation. This neutrophilic pusutulosis is primarily noted in children of color. Vertical transmission of viruses can range from benign lesions seen in molluscum transmission to herpetic lesions that can cause failure to thrive and neurodevelopmental changes due to encephalitis. The latter can be confirmed with direct fluorescent antibody or Tzanck smear and requires intravenous acyclovir. Scabetic lesions can mimic the above with lesions in the axillae, diaper region and palms and soles; scabies in the neonate requires mineral oil preparation for diagnosis, and treatment of the entire family.
Other issues noted in neonates are nevi. Nevus sebaceous of Jadassohn occurs in an estimated three out of 1000 neonates and presents as a sharply circumscribed yellow orange hamartoma that varies in size, usually on the scalp or less likely the head and neck. At puberty, neoplasms can arise in the lesion, and can be masked by the hypertrophy that occurs concurrently. Excision to reduce the 10–15% malignancy risk is recommended at or prior to puberty.[22]
Other important issues to note on the scalp are the hair collar sign, a ring of dark, long hair encircling a lesion, often an area of abnormal skull and/or underlying brain development. New evidence suggests that karyotype abnormalities and spinal dysraphism can be associated. Imaging of the head and spine with a MRI or CT scan with bony tables, along with a karotype and neurosurgical consultation, should be performed.[23] Even without a surrounding hair collar, glabellar nodules also herald neural tube closure defects. Transillumination can be helpful. If the lesion is light conductive, than a nasal glioma or a menigioma should be considered. If light is not conducted, than a dermoid tumor or hemangioma of infancy is more likely. An MRI and magnetic resonance angiography should be performed if vascularity is suspected, and a neurosurgical consultation may be needed.
More common benign lesions include Mongolian spots, bluish hyperpigmented patches on the lower back seen in 61.6% of Asian infants, 71.3% of Arabic infants and 74.8% of infants of African descent. They can also occur eccentrically on other areas of the body, but most resolve by 6 years of age.[24]
Café au lait macules are smooth-edged oval tan macules oriented along skin lines. They represent localized excess pigment production and occur in 3% of infants and 25% of healthy children. Recent studies demonstrate that six or more café au lait spots remains the first and most sensitive of the indicators of neurofibromatosis in children.[25]
Hypopigmentation can appear in a variety of patterns, including nevus depigmentosus, a benign area of less pigmentation, similar in shape to café au lait macules. These lesions are common in patients of color. Hypopigmentation in the lines of Blaschko is termed pigmentary mosaicism and can be associated in 20–30% of cases with neurodevelopmental anomalies, the so-called 'hypomelanosis of Ito' syndrome. Karyotype is indicated along with close neurodevelopmental follow-up. Congenital hypopigmentation can be noted in tuberous sclerosis, following a confetti, ashleaf or thumbprint pattern. The associated classic triad includes adenoma sebaceum, mental deficiency and epilepsy. Other associated features include periungual fibromas, shagreen plaques (collagenomas), oral papillomatosis, ash leaf hypomelanotic macules, skin fibromas and café au lait macules. New exciting research demonstrates that mTOR inhibitors prevent the development of epilepsy and underlying brain abnormalities with epileptogenesis in mouse models. The ramifications on cutaneous disease are unknown.[26]
Congenital melanocytic nevi can be classified as small (under 1.5 cm), medium (1.5–20 cm) or giant (greater than 20 cm or encompassing a complete body region). These giant congenital melanocytic nevi tend to have lumps, bumps and irregular features. They require close follow-up and a MRI of the head to rule out leptomeningeal melanocytosis, which can cause progressive neurological degeneration. Melanoma can be noted in 4% of giant congenital melanocytic nevi and can be cutaneous or intracranial.
Nevus simplex is a catch-all term for stork bites, or angel kisses. Outside the scalp location there is a tendency for resolution, but when it does involve the scalp, persistence into adulthood can occur in 25% of patients. A port wine stain (PWS) is a vascular malformation. Underlying vascular malformations account for associated syndromes, including overgrowth in Klippel–Trénaunay syndrome, due to lymphatic malformation, Sturge–Weber syndrome (encephalotrigeminal angiomatosis) in V1 PWS and glaucoma in V2 PWS. Ophthalmology referral and pediatric dermatology referrals should be given. A MRI should be performed if there are seizures or developmental delay. Treatment with a pulsed dye laser can help to improve cosmesis and self-esteem.
The common vascular tumor, hemangioma of infancy (HOI), begins at a few weeks of life and can enlarge rapidly, mostly in the first quarter of the first year, but continued enlargement can be seen from 9 to 12 months. Resolution can start around 1.5 years of age, with 30% resolved at 3 years of age, 50% at 5 years, 70% at 7 years and 90% at 9 years. Referral to a dermatologist is warranted if there is a question of facial scarring, nasal involvement called the Cyrano deformity, interference with feeding, ulceration or a possible syndrome present. Syndromes associated with HOI are: PHACE syndrome, beard hemangiomas and SACRAL syndrome. PHACE syndrome includes posterior fossa anomalies, hemangioma of infancy (segmental/flat facial), arterial defects, cardiac anomalies/aortic coarctation, eye anomalies and sterna notch or supraumbilical raphe. Beard hemangiomas are hemangiomas of infancy within the lower third of the face, pre-auricular area, or the chin and neck. The greater proportion of these areas affected, the greater the risk of airway compromise. A MRI of the head and neck is warranted in this situation. SACRAL stands for spinal dysraphism, anogenital anomalies, cutaneous manifestations, renal and urologic anomalies, angioma and lumbosacral involvement. Indications for intervention include severe hemorrhage, cardiovascular compromise from high-output cardiac failure, nasal or auditory canal obstruction, hepatic hemangiomatosis, skin ulceration or threatened interference with vital functions. Oral prednisone at 2–4 mg/kg/day, recombinant IFN-a2a or -2b, or propranolol can be used. Pulsed-dye laser is especially helpful in the setting of ulcerated HOI.