Epidermal Nevus Syndrome Differential Diagnoses

Updated: Mar 23, 2021
  • Author: Robert A Schwartz, MD, MPH; Chief Editor: William D James, MD  more...
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Diagnostic Considerations

The ichthyosiform nevus of CHILD syndrome (congenital hemidysplasia with ichthyosiform erythroderma and limb defects syndrome) resembles inflammatory linear verrucous epidermal nevus, but CHILD syndrome has yellowish waxy scaling and histologic features of a verruciform xanthoma. Linear psoriasis with papules in a linear configuration may represent a Koebner reaction. Linear psoriasis is distinct from inflammatory linear verrucous epidermal nevus because linear psoriasis develops either later in life in patients with plaque-type psoriasis or as congenital plaque-type psoriasis with subsequent linear distribution along the lines of Blaschko. Inflammatory linear verrucous epidermal nevus and psoriasis each have a different protein analysis and a different pattern of epidermal keratin 16 and keratin 10 expression.

Other linear eruptions may clinically resemble inflammatory linear verrucous epidermal nevus and linear epidermal nevus; however, their histologic findings usually distinguish them. Lichen striatus (LS) tends to occur in children rather than in adults. LS consists of discrete erythematous, scaly, flat-topped asymptomatic papules on 1 of the extremities. LS has a sudden onset and spontaneous regression within 1 year.

Linear lichen planus typically occurs in children, in whom the characteristic discrete pruritic polygonal violaceous papules are arranged in a linear fashion, usually extending along an entire limb. Linear porokeratosis is a childhood disorder characterized by small, ringlike, hypertrophic verrucous plaques with a linear morphology usually limited to a single extremity. At times, linear lichen simplex chronicus, linear Darier disease, linear lichen nitidus, and linear human papillomavirus–induced warts may require differentiation from linear epidermal nevus and inflammatory linear verrucous epidermal nevus.

Linear epidermal nevus in the genital area may be mistaken for genital warts. [31]

Trichoblastomas with Merkel cell proliferation in nevi sebacea in Schimmelpenning-Feuerstein-Mims syndrome may facilitate histological differentiation between trichoblastomas and basal cell carcinomas. [32] The detection of multiple Merkel cells within the epidermal layer by cytokeratin 20 staining was considered to be an important clue. A study of 707 cases of nevus sebaceus itself documented trichoblastoma in 7.4%, the most common benign tumor, followed by syringocystadenoma papilliferum in 5.2% and basal cell carcinoma in 2.5%. [33]

A new entity, labeled keratinocytic epidermal hamartoma syndrome, has been described as a papular epidermal nevus with a "skyline" basal cell layer. [34, 35]

Differential Diagnoses