Author: Kawaroreet Karwal MS2, Y, Miller-Monthrope, Dermatologist/Dermatopathologist, Toronto, Canada, 2024

Definition: Epidermal nevus is a benign skin condition characterized by the overgrowth of epidermal cells, resulting in the formation of warty or verrucous plaques. 

Etiology: These lesions typically present at birth or develop early in childhood and can persist throughout life.

Epidemiology: Epidermal nevi are rare, occurring in approximately 1 in 1,000 live births. They are most commonly found on the trunk, limbs, and neck. 

Signs: The lesions are often linear or segmental, following the lines of Blaschko, and can vary in colour from flesh-toned to brown.

Symptoms: Symptoms associated with epidermal nevus include pruritus and irritation, particularly if the lesions are inflamed or become secondarily infected. In rare cases, epidermal nevi can be part of broader syndromes, such as epidermal nevus syndrome, which may involve neurological, skeletal, and ocular abnormalities.

Treatment: Treatment for epidermal nevus is primarily aimed at managing symptoms and improving cosmetic appearance. Options include topical treatments, such as keratolytics and retinoids, and surgical interventions like excision, laser therapy, or cryotherapy. The choice of treatment depends on the size, location, and symptoms associated with the nevus.

References:

1.     Hafner, C., & Vogt, T. (2008). Sebaceous Gland Disorders. In Harper’s Textbook of Pediatric Dermatology (Vol. 2, pp. 235-246). Wiley-Blackwell.

2.     Happle, R. (2000). The group of epidermal nevus syndromes part I. Well-defined phenotypes. Journal of the American Academy of Dermatology, 42(2), 171-183.

3.     Patel, S., Zirwas, M., & English, J. C. (2010). Treatment of epidermal nevi: a systematic review. Journal of the American Academy of Dermatology, 62(1), 19-28.