Epidermal nevus (overview) D23.L

The designation "epidermal nevus" as hamartoma of the skin, refers to v. Baerensprung, who first used the designation "Naevus unius lateris" (cited in Su et al.) for a systematized verrucous nevus in 1863.

Inflammatory or non-inflammatory, reddish-brownish or dirty-brownish, soft-papillomatous or wart-like-hard malformations of the epidermis (often with a dermal component), which are congenital or appear in the first years of life and can be interpreted as a cutaneous mosaic, and which, apart from the CHILD syndrome, manifest themselves in the Blaschko lines or as other cutaneous mosaics.

Various epidermal nevi are to be considered as monitoring signs of complex syndromal malformations.

The following distinctions can be made:

• Simple (non-organoid) epidermal nevi (affecting only the epidermis)
• Compound "organoid" epidermal nevi (involving epidermis and skin appendages)
• Epidermal nevi as monitorial signs for syndromes.
  • Epidermal nevi:
    • Papillomatous (soft) epidermal nevus (postzygotic mutations in FGFR3,PIK3CA, KRAS genes)
    • Verrucous (hard) epidermal nevus (nevus verrucosus
      )Special form: nevus
      verrucosus unius lateralis
    • ILVEN
    • Epidermolytic epidermal nevus (minus variant of keratosis plamoplantaris diffusa with mutations in keratin1)
    • CHILD syndrome
    • Corniculatus nevus
    • Segmental M. Darier
    • Segmental M. Hailey-Hailey ( Pemphigus chronicus benignus familiaris)
    • Linear porokeratosis (linear manifestation of disseminated superficial actinic porokeratosis)
    • Linear manifestation of plaque-like porokeratosis mibelli
  • Organoid (compound) epidermal nevi:
    • Nevus sebaceus (proven mutations in the HRAS gene)
    • Nevus comedonicus
    • Porokeratotic eccrine ostium nevus (PEODDN)
    • Hamartoma, eccrine
    • Becker nevus
    • Hair nevus (see also curlyhair nevus)
    • Munro's naevus.
  • Epidermal nevi as monitoring signs for syndromes.
    • Schimmelpenning-Feuerstein-Mims syndrome
    • Proteus syndrome
    • Child syndrome
    • Phakomatosis pigmentokeratotica
    • Nevus comedonicus syndrome
    • Angora hair nevus syndrome
    • Becker nevus syndrome.

The incidence is estimated at 1:1000 children. In a larger study with 131 nevi occurring up to 14 years of age, 80% of the nevi were present at birth (Rogers M et al. 1989).

From a histopathological point of view (cited in Su 1982) the following classification results:

1. acrokeratosis verruciformis-like
2. Epidermolytic-hyperkeratotic
3. Seborrheic keratosis-like
4. Psoriasiform (eczematoid) - inflammatory linear verrucous epidermal nevus = ILVEN
5. Wart-like (verrucous)
6. Porokeratosis-like
7. Acantholytic
8. Comedon-like

1. The A et al (2014) Linear non-epidermolytic verrucous epidermal nevus. Indian Pediatr 51:591
2. Fan YM et al (2014) An atypical variant of phacomatosis pigmentokeratotica: verrucous epidermal nevus, speckled lentiginous nevus, and pointed nevus associated with scoliosis. Int J Dermatol 53: 619-621
3. Kruse LL et al (2015) Differential Diagnosis of Linear Eruptions in Children. Pediatr Ann.44:e194-e198
4. Su WP(1082)Histopathological varieties of epidermal nevus. A study of 160 cases. At J Dermatopathol 4:161-170
5. Rogers M et al (1989) Epidermal nevi and the epidermal nevus syndrome.
   A review of 131 cases. J Am Acad Dermatol 20:476-88.
6. Waghmare RS et al. (2013) Inflammatory linear verrucous epidermal nevus. J Assoc Physicians India 61:431-432