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Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z



Nail diseases

This page outlines the terms used by dermatologists to describe diseases of the fingernails and toenails.

Abnormalities of the nail plate surface

Nail plate abnormalities are often due to inflammatory conditions affecting the matrix or nail bed. Specific diagnoses may be made from characteristic appearances.

Pitting
Consider eczema, psoriasis (haphazard: upper image), alopecia areata (regular: lower image)
Nail psoriasis pitting
Alopecia areata nail pitting
Transverse ridging
Consider eczema (top image), paronychia (middle image), psoriasis, parakeratosis pustulosa, Beau's line (affects all nails, due to acute systemic illness stopping nail growth: lower image)
Nail ridges due to eczema
Nail ridging due to eczema
Beau line of nail
Onychorrhexis
Longitudinal ridging. Consider aging (top image), lichen planus (middle image), psoriasis, fungal nail infection, Darier (bottom image) or a habit of picking
Longitudinal nail ridging
Lichen planus of nails
Darier nail disease
Longitudinal groove
Median canaliform dystrophy
due to Myxoid cyst (image) or wart
Nail groove due to myxoid cyst
Median nail dystrophy
Feathered longitudinal ridge
2nd image: © Dr Ph Abimelec – dermatologue
Median canliform dystrophy
Median canaliform dystrophy
Onychogryphosis
Thick hard curved nail plate in the shape of a ram's horn.
due to aging (image), psoriasis or trauma
Onychogryphosis
Onychogryphosis
Onychauxis
Thick nail due to psoriasis (top image), trauma or fungal nail infection (bottom image)
Psoriatic nail dystrophy
Fungal nail infection
Angel-wing deformity
Nail plate thinning due to lichen planus
Nail plate crumbling
Typical of psoriasis (top image) & fungal nail infection (bottom image)
Nail dystrophy due to psoriasis
Nail dystrophy due to onychomycosis
Onychoschizia
Distal lamellar splitting/brittle nails due to water/detergent damage
Nail splitting: onychoschizia
Longitudinal splitting
An extension of ridging seen in psoriasis, fungal nail infection (top image) or lichen planus (bottom image)
Bottom image ©R Baran
Longitudinal splitting of nail
Nail splitting due to lichen planus
Distal notching
Consider Darier (image) and lichen planus
Darier nail disease
Trachyonychia
Rough nails. If all nails affected, known as Twenty Nail Dystrophy, probably due to lichen planus
Twenty nail dystrophy trachyonychia
Erosion
Consider trauma or malignant tumour e.g. SCC or melanoma (image)
Melanoma of nail
Acrylic nails
Decorative cosmetic
Acrylic nail
Nail cosmetics

Nail discolouration

Distinguish a discoloured nail bed from a discoloured nail plate.

Yellow nail syndrome
Yellow or green nails due to lymphatic obstruction in cardiopulmonary disease
Yellow nails
Yellow nails
Green nails
Pseudomonas/candida infection
Candida nail infection
Yellow nails
Due to fungal nail infection
Fungal nail infection
Lateral yellow streak
Due to dermatophyte onychomycosis
Onychomycosis
Yellow nails
Due to psoriasis
Nail psoriasis
Oil-drop or salmon patch
Due to psoriasis: orange or brown streak proximal to onycholysis
Psoriatic nail dystrophy
Brown nails
Consider staining (nicotine, potassium permanganate, nail varnish) and chemotherapy. Illustrated are staining from podophyllin (top image) and streaks due to oral hydroxyurea (bottom image).
Nail staining
Nail discoloration due to hydroxyurea
Vitiligo
White nails and adjacent skin
White nail due to vitiligo
Leukonychia
White nails. Consider hypoalbuminaemia or chronic renal failure. May be familial. Transverse leukonychia, or multiple parallel white lines, are thought to be due to manicuring but may also arise in association with Beau's lines.
White streaks
Traumatic e.g. manicuring
White spots on nail
White spots on nails
Transverse leukonychia
Onycholysis
White or yellow distal nail, lifted off. Consider idiopathic causes (top image), trauma, psoriasis (second image), thyrotoxicosis, irritant & allergic contact dermatitis, fungal nail infection (candida: third image), drug photosensitivity (especially tetracycline: bottom image; and psoralens)
Onycholysis
Psoriatic onycholysis
Nail candidiasis
Photoonycholysis
White spotting
Due to superficial white onychomycosis
Onychomycosis
Half-and-half nails
Seen in renal failure. White proximal nail, brown distal nail
Half and half nail
Terry's nails
Seen in liver cirrhosis. White proximal nail, reddened distal nail
Terry nail
Terry nail
Mee's lines
Partial leukonychia due to arsenic intoxication or systemic disease
Muehrcke's lines
Double band of leukonychia in renal disease
Muehrcke nail
Red lunula Red lunula
Red longitudinal streak
Erythronychia due to trauma
Erythronychia
Red & white streaks
Seen in Darier disease
Darer nail erythronychia
Red tender area
Consider glomus tumour
1st Image ©R Baran
2nd image © Dr Ph Abimelec – dermatologue
Glomus tumour of nail
Glomus Tumour
Blue nail
Consider drugs (all nails affected), in this case minocycline
Blue nails due to minocycline
Red/purple streak
Splinter haemorrhage
Splinter haemorrhages
Purple/black nail
Haematoma (blood clot)
Subungual haematoma
Black nail
Pseudomonas infection
Black nails with pseudomonas infection
Brown/black linear streak
Benign melanocytic naevus.
Melanonychia
Multiple brown linear streaks
Also called longitudinal melanonychia. May be of racial origin or Laugier-Hunziker Syndrome. Rarely due to drug (azidothymidine, tetracycline), endocrine disorders or Peutz-Jeghers syndrome.
Multiple melanonychia
Expanding variable colour/shaped streak
Consider melanoma
Bottom image ©R Baran
Nail melanoma
Subungual melanoma

Abnormalities of the cuticle and nail fold

The cuticle is an area of keratin joining the skin of the posterior nail fold to the nail plate. Loss of cuticle reuslts in paronychia.

Ragged cuticles
Connective tissue disease, parakeratosis pustulosa
Ragged cuticles
Hang nail
Trauma (biting)
Hang nail
Nail fold telangiectases
Connective tissue disease e.g. lupus erythematosus
Nail fold telangiectasia
Vasculitis
Distal digital infarcts
Nail infarction
Subungual hyperkeratosis
Scaling under hyponychium. Typical of psoriasis (top image) & onychomycosis but also arises in crusted scabies (bottom image)
subungual hyperkeratosis
Crusted scabies with scaling under nails
Pterygium
Due to scarring in nail matrix. Characteristic of lichen planus (image) but may occur in Stevens-Johnson syndrome and from trauma
Pterygium of nail due to lichen planus
Acute paronychia
Staphylococcus aureus
Acute paronychia
Acute paronychia
Herpes simplex
Acute herpetic paronychia
Chronic paronychia
Candida albicans or pseudomonas
Chronic paronychia
Acrodermatitis continua of Hallopeau
Acrodermatitis continua of Hallopeau is a form of severe psoriasis
Acrodermatitis continua
Retronychia
Embedding of the nail into the nail fold and subsequent inflammation.

Abnormalities of nail shape

Enlarged
Osteoid osteoma (bone tumour)
©R Baran
Nail enlargement due to osteoma
Long
Uncut
Uncut nail
Brachyonychia
Short
Over-curvature
Resorption of distal phalanx
Overcurvature of nail
Clubbing
Due to hypertrophic osteoarthropathy (image) or thryoid disease (acropachy)
Clubbing of nail
Koilonychia
Thin spoon-shaped nail associated with iron deficiency anaemia & acitretin treatment
©R Suhonen
Koilonychia
Pachyonychia
Wedge-shaped nails
Pachyonychia
Pincer nail
Sometimes familial or associated with psoriasis
Pincer nail deformity
Onychocryptosis
In-growing nail with granuloma formation. Aggravated by retinoids such as isotretinoin or acitretin
Ingrowing nail

Loss of nails

Without scarring
Usually traumatic eg nail biting; in children parakeratosis pustulosa
Nail biting
Bitten nail
Scarring
Due to tumour (upper image) or erosive lichen planus (bottom image)
Bottom image © R Baran
Nail loss due to melanoma
Nail loss due to lichen planus
Onychomadesis
Nail shedding may arise in severe or bullous lichen planus (image) or acute and severe systemic illness
Nail shedding due to lichen planus
Nail patella syndrome
© Dr Ph Abimelec – dermatologue
Nail dystrophy in nail patella syndrome

Lesions around nails

Common skin lesions around nails include:

Viral warts Periungual warts
Melanocytic naevus Melanonychia
Subungual melanoma Subungual melanoma
Squamous cell carcinoma or keratoacanthoma (image)
©R Baran
Subungual squamous cell carcinoma
Corn Corn
Subungual fibroma
2nd image © Dr Ph Abimelec – dermatologue
Periungual fibroma
Subungual fibroma
Inclusion cyst
© Dr Ph Abimelec – dermatologue
Inclusion epidermal cyst
Onychomatricoma
© Dr Ph Abimelec – dermatologue
Onychomatricoma
Subungual exostosis Subungual exostosis
Giant cell tumour of tendon sheath
© Dr Ph Abimelec – dermatologue
Giant cell tumour of tendon sheath
Myxoid cyst Myxoid cyst
Pyogenic granuloma Periunguagl pyogenic granuloma

Related information

References:

On DermNet NZ:

Other websites:

Author: Dr Amanda Oakley, Clinical Associate Professor, Waikato Clinical School.

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