Longitudinal section of a digit showing the dorsal nail apparatus.
Clubbing: Lovibond's profile sign. The angle is normally less than 160° but exceeds 180° in clubbing.
Nail pterygium due to lichen planus.
Trachyonychia: roughened surface of up to 20 nails.
Green pigmentation of onycholytic fingernail due to Pseudomonas .
(a) Longitudinal erythronychia. (b) The longitudinal ridge in the nail bed corresponds to the groove on the undersurface of the nail plate.
Nail biting can be extensive, with damage to the nail folds and nail plate causing subungual haemorrhage.
(a,b) Ingrowing great toenail complicated by proximal ingrowing (retronychia).
This lesion was mistaken for an ingrowing toenail. X‐rays confirmed the presence of subungual exostosis.
Submatricial fibrokeratoma pressing onto the underlying matrix with subsequent longitudinal smooth groove.
X‐rays showing massive osteolysis of the distal bony phalanx associated with subungual keratoacanthoma.
Superficial fibromyxoma of the nail bed elevating the distal plate.
Narrow longitudinal melanonychia on a thumb. Dermoscopy showed loss of parallelism that prompted excisional biopsy. Histological examination revealed ...
(a–c) Chronic paronychia: paronychial swelling, loss of cuticle and mildly dystrophic nail in early disease (a,b); severe nail dystrophy in more advan...
Multiple transverse grooves of the thumbnails.
Lichen planus with longitudinal melanonychia.
Ultrasound: grey scale ultrasound (longitudinal view) demonstrates the normal sonographic anatomy of the nail (a); 3D ultrasound reconstruction of the...
Normal nail fold capillaries (×60) (a); acrocyanosis showing dilatation of the nail fold capillaries, stasis and thrombosis of many vessels (b); rheum...
(a) Avulsion of the proximal third of the plate demonstrates that the pigment area responsible for the pigmentation extends longitudinally on the matr...
(a) Dermatophyte onychomycosis with longitudinal spikes. (b) After surgical removal of the yellow streaks.
(a) Ingrowing toenail with pyogenic granuloma. (b) After curettage of the pyogenic granuloma, a lateral strip of nail is avulsed. (c) A cotton‐tipped ...
Direction of differentiation and cell movement within the nail apparatus.
Clubbing: Curth's modified profile sign.
Anonychia: nail loss in a 50‐year‐old man with dominant dystrophic epidermolysis bullosa.
Ventral pterygium due to allergy to formaldehyde nail hardener.
Onychoschizia (lamellar splitting).
Transverse ridges resulting from habit tic.
Early onychogryphosis of the left great toenail.
Pyogenic granuloma resulting from friction of the overlapping second toe against the lateral aspect of the great toenail.
Digital myxoid pseudocyst type A.
Intraungual (dissecting) fibrokeratoma. The lesion grows within the nail plate and emerges at its distal half.
Onychomatricoma, pigmented variant: note the very well‐delimited longitudinal thickening of the plate.
Onychopapilloma: note the longitudinal erythronychia starting in the distal matrix, the distal splinter haemorrhages and the onycholysis at its distal...
Friable granulation tissue under the plate of the great toenail in an old lady wearing sandals all year round. Pyogenic granuloma was suspected but hi...
Painful dorsolateral fissure of the fingertip.
Psoriasis: salmon patches progressing to onycholysis.
Acropustulosis: nail plate has been destroyed by intense pustular inflammation.
Anonychia following lichen planus.
Nail melanoma: clinical presentation (a); dermoscopy (b) and in vivo reflectance confocal microscopy (c) of the nail matrix in the same patient. (C...
Dermatomyositis showing dilated nail folds capillaries and obstructed and thrombosed capillaries (×60) (inset).
(a) Avulsion of the proximal third of the plate exposes the wide pigment area responsible for the longitudinal pigmentation. (b) An incision is carrie...
(a) Chronic paronychia resistant to topicals and steroid injections. (b) Crescent‐shaped excision of a part of the proximal nail fold. (c) Complete re...
Allergy to nail varnish presenting as an eyelid dermatitis.
Arterial supply of the distal finger.
Schamroth's window is seen clearly in this image of normal nails.
Onycholysis: idiopathic type.
Median canaliform dystrophy of Heller.
Longitudinal ridging of the nail.
Median canaliform dystrophy of Heller affecting distal portion of nail plate; the enlarged lunula and transverse ridging seen proximally reflect chron...
Severe onychogryphosis resulting from neglect.
Painful glomus tumour of the nail bed. Note the bluish hue.
Digital myxoid pseudocyst type B. Note the longitudinal groove arising from underneath the proximal nail fold where the matrix is compressed by the ov...
Multiple soft fibrokeratomas in tuberous sclerosis.
Onychomatricoma: ‘woodworm’ cavities in the nail plate are especially visible in this longstanding case (>40 years).
Bowen disease: warty lesion of the distal bed and hyponychium. The lesion was treated for several years as a wart.
Acute bacterial paronychia (whitlow).
Psoriasis: distal onycholysis.
Darier disease: white and red longitudinal lines and distal notching.
Paronychia of the little finger in a 2‐year‐old child.
Axial T2‐weighted image at the level of the distal interphalangeal joint (arrows): pedicle of the myxoid pseudocyst connected with the joint (arrows) ...
Lupus erythematosus (a) and systemic sclerosis (b). (Courtesy of the copyright holder C. Mathis, Belgium.)
Lateral longitudinal biopsy. Note the sigmoid shape of the defect that can be easily closed.
Two lateral incisions at 45° allow reflection of the proximal nail fold; visualization of the tumour and its removal.
Staining of the nail plates from nail varnish.
Proliferating epithelial cells of the matrix and ventral aspect of the proximal nail fold, staining with the antibody MIB‐1.
Koilonychia. This image is of congenital koilonychia in a young girl.
Photo‐onycholysis with a uniform pattern of discoloured onycholysis in the midline.
Beau's lines present as transverse grooves in the nail matching the proximal margin of the nail matrix and lunula.
Orange pigmentation of onycholytic toenail due to orange dye from work‐boots.
Yellow nail syndrome
(a–c) Onychogryphosis is often best treated with ablation of the nail matrix.
Subungual exostosis: exophytic growth of bone emerging from under the nail plate through collarette of skin (note the telangiectases) (a); exostosis ...
Digital myxoid pseudocyst type C. Note the red macule within the lunula.
Subungual distal keratoacanthoma. Note the keratotic plug on the distal bed.
Onychomatricoma: showing the sea anemone‐like matrix tumour and the cavities in the avulsed nail plate into which digitate projections from the tumour...
Onycholysis and oozing of the great toenail bed due to invasive squamous cell carcinoma.
Subungual abscess in neutropenic patient receiving cancer chemotherapy. (Courtesy of B. Fouilloux, France.)
Psoriasis: subungual hyperkeratosis.
Severe onychatrophy from juvenile onset lichen planus of nails.
Transverse acro‐osteolysis of the fingernail (a); acro‐osteolysis of the toenail (b). (Courtesy of J. L. Drapé, France.)
Sagittal section T2 fat saturated image: pedicle connecting with the joint (arrow) under the extensor tendon (arrow heads). (Courtesy of the copyrigh...
(a) Avulsion of the proximal third of the plate exposes the pigment area responsible for the longitudinal pigmentation. (b) A 3 mm punch is performed ...
Lateral avulsion (‘sardine tin’ avulsion) allows exposure of the complete nail bed and excisional biopsy of the nail bed tumour.
Trap door avulsion permits access to the nail bed tumour. The latter will be removed in a longitudinal excision.
Complication of nail extensions: allergy to acrylate adhesive presenting as onycholysis.