Intra-Operative Onychoscopy of Subungual Epidermoid Inclusions

Subungual epidermoid inclusions (SEI) are small epithelial inclusions, sometimes solid but mostly with central keratinization of the onycholemmal type without a granular layer. Exceptionally, they become large enough to produce symptoms such as pain or swelling of the nail bed, resulting in subungual keratosis, onycholysis, or a dystrophic nail plate. Herein, we report a further case of SEI in a female patient with onychodystrophy of the great toe nail and highlight the onychoscopic features of SEI. Intra-operative onychoscopy facilitates the detection of SEI during a nail bed biopsy and reduces the risk of obtaining inadequate specimens for histopathologic examination.