Epidermal Nevus
Epidermal nevus
 congenital hamartomas of embryonal ectodermal origin classified on the basis of
their main component:
1. non-organoid
i. keratinocytic
2. organoid
i. sebaceous
ii. apocrine
iii. eccrine
iv. follicular
 1/3rd will have involvement of other organ systems – use of the term syndrome
denotes these cases
Clinical
 often present at birth but may develop as late as adolescence
 In the newborn, the nevi are linear or ovoid, flat, velvety plaques. During
adolescence, the lesions become more raised, verrucous, and hyperpigmented.
 often asymptomatic; however, inflammatory linear verrucous epidermal nevi are
pruritic
 characteristic epidermal nevus is a linear, hyperpigmented plaque, which can vary
from pink to black, velvety to verrucous, subtle to thick, and limited to extensive.
 typically occurs on the trunk or extremities along the lines of Blaschko but
may occur on the face and neck.
 often do not cross the midline
 lines are thought to represent examples of cutaneous mosaicism in embryologic
development.
 Only sebaceous nevus associated with other cutaneous malignancies
o Basal cell carcinoma, the most commonly associated secondary
cutaneous malignancy, typically does not occur until after puberty (1020%)
o Squamous cell carcinoma is a rare complication of sebaceous nevus,
but has been reported.
Epidermal Nevus Syndromes
 group of congenital neurocutaneous disorders characterized by epidermal nevi in
association with cerebral, ocular, skeletal, and sometimes cardiac and renal
abnormalities.
Proteus syndrome
 rare condition that can be loosely categorized as a hamartomatous disorder. It is a
complex disorder with multisystem involvement and great clinical variability.
 characterized by a variety of cutaneous and subcutaneous lesions including
vascular malformations, lipomas, hyperpigmentation, and several types of nevi.
 Partial gigantism with himifacial, limb or digital overgrowth is pathognomonic
with an unusual body habitus and, often, cerebriform thickening of the soles of
the feet.
 Exceptionally large digits may require surgical reduction in extreme circumstances
so that the patient can wear shoes or use a hand.
 Hemifacial macrosomia or macroglossia may require surgical intervention if
airway obstruction, feeding difficulties, or severe malocclusion is present.
Management
 presence of multiple epidermal nevi in an infant should prompt consideration of
other organ abnormalities.
 A complete prenatal, perinatal, and neonatal history should be taken, in addition to
a thorough physical and developmental examination, with special attention paid to
examination of the eyes, head circumference, spine, extremities, and central and
peripheral nervous systems.
 Establishing the diagnosis and screening for associated abnormalities may involve
skin biopsies, blood chemistries, chest and skeletal radiographs, urinalysis,
electroencephalograms, computed tomography or magnetic resonance imaging,
echocardiography, abdominal ultrasonography, and serum and urine measurements
of calcium and phosphorus metabolism.
 Management of ENS requires a multidisciplinary approach.
 treatment of choice for epidermal nevi is excision.
 preferable to delay surgery until the lesion has clinically reached its final growth
extent, since early excision may result in recurrence.
 For larger lesions, excision may lead to significant scarring
 Other treatments include:
i. topical and intralesional glucocorticoids,
ii. topical and systemic retinoids
iii. topical 5-fluoruracil
iv. dermabrasion
v. liquid nitrogen cryotherapy
vi. laser therapy
vii. deep shave excision
 some of these modalities may provide adequate short-term results, but in most
cases, recurrence is common
 Success with laser therapy is variable and is related to the type of lesion and its
clinical characteristics