Ectopic Foot Nails: Clinical and Dermoscopic Features, Treatment and Outcome in 20 Cases

Abstract

Background: Ectopic nail (EN) is an extremely rare condition in which the small nail apparatus grows outside the normal nail unit of the hand and fingertips. Limited data can be found in the literature regarding ectopic nails of the foot and toes (EFN). Objective: The study aimed at characterizing the clinical, therapeutic and dermoscopic EFN by a comparison with and differentiation from EN observed on the hands. Methods: Data on EFN collected during 2004-2014 were analysed. A literature search was performed to evaluate articles for review points on the topic. Results: Characteristics of shape, development, ultrasound aspects, dermoscopy and the response to treatment of 22 EFN were reported. Results from our study were compared with cases reported in the literature. Conclusion: In this article, new aspects on EFN from the clinical-morphological and dermoscopic points of view are reported; these may facilitate the diagnosis of an anomaly even without a histological examination.

Onychoheterotopia in children

“…Histopathological and ultrastructural features are similar to those of a regular nail with a reverse growth pattern. 4 Three zones constitute EN: nail matrix, nail bed, nail plate, similar onycholysis, but differently arranged compared to a standard nail. 5 The EN has a matrix in the center or back, with a horizontal-vertical growth pattern and a distal or inverted orientation.…”

Multiple pebble‐like ectopic nails as a subsequent complication of phenol cauterization treatment for onychocryptosis

“…The association of hair curling and acitretin, as well as other systemic retinoids, has been already reported a few times. [1][2][3] However, most of the previous reports failed to present whether or not the eventual resolution of the hair change occurred. Furthermore, there has been no report of pronounced retinoid-induced curling of hair in an Asian.…”

“…Patients with ectopic nails usually have only one lesion, and even double lesions are unusual. 1 In almost all cases, the ectopic nails protrude from the skin surface, 1 and only one subcutaneous case has been reported. 2 The present case is novel and unique in that there were dozens of tiny ectopic nails in a nodule.…”

A Tale of a Double-Nailed Toe

“…Our case of ectopic plantar nail appeared as a keratotic prominence with an intradermic implanted base and a well-defined horizontal orientation just as a normal nail. Ectopic foot nails may lead to an impairment of the foot function, difficulty in walking, and cosmetic disfigurement [3]. Diagnosis is often based on histopathologic examination of the nail tissue.…”