Surface Anatomy of the Nail for the Dermatologist

Abstract

Expert diagnosis of cutaneous pathology requires precise anatomic description. In this brief report the authors review the clinically relevant surface anatomy of the nail and relate it to a case of squamous cell carcinoma.

Digital Anaesthesia and Relevant Digital Anatomy for the Dermatologist

“…Contraindications are few and include compromised digit circulation, infected injection site, and known allergy to local anaesthetic. 3 It is very important to know the appropriate anatomy as this increases the safety and efficacy of the injections. In addition, skill in administering these injections vastly improves patient comfort and safety.…”

“…These include nail biopsies, laceration repair, and more involved nail surgeries like skin cancer removal. 1-3 The palm, nails, and volar fingers are very sensitive, and local injection of anaesthetic can be extremely painful in these locations. Digital anaesthesia can be accomplished by all proximal or distal digital nerve blocks and with greater predictability and less discomfort than local infiltration.…”

Squamous Cell Carcinoma of the Nail, an Underdiagnosed and Underestimated Entity: A Series of Two Cases

“…In case of bone invasion, amputation of the distal phalanx or disarticulation of the affected finger is recommended [1,11], being the latter treatment the one with the lowest recurrence rate [7]. In case 2, despite having bone involvement, opted for resection to the periosteum and not amputation gave the functional importance of the first finger (an opposite finger for clamp action).…”

“…If there is no osseous invasion, a wide local resection should be performed, however, there is no clear information available on the optimal surgical margins [11]. A resection margin of no less than 4 mm has been recommended in some publications [7], however, other bibliographies recommend a margin of 5 mm [1].…”

“…The nail apparatus is a complex area with great functional and cosmetic importance [1]. The appearance of tumors is rare but given the special anatomical location, they usually show morphological and clinical differences compared to similar lesions located in other parts of the skin [2], causing them to be frequently misdiagnosed as dermatoses, viral warts, or fungal infections, delaying the diagnosis on average five to seven years [3].…”