logo Examination of the nails

Introduction to dermatology

Examination of the nails

Objectives

  • To develop skills in examining the nails

Key points

Diseases of the nail apparatus may result in:

  • Abnormalities of nail plate surface.
  • Nail plate discolouration.
  • Abnormalities of the cuticle and nail fold.
  • Abnormalities of nail shape.
  • Complete loss of nails.
  • Lesions around nails.

Examination of the nails

This section provides a glossary of terms used to describe abnormal fingernails and toenails. Proper use of language is necessary for diagnosis and to communicate with other health professionals.

Nails are a specialised form of stratum corneum and are made predominantly of keratin. Their primary functions are for protection, scratching and picking up small objects. When looking at the nails carefully inspect the nail plate and surrounding skin.

Normal nail

If the patient presents with a nail problem, it’s important to ask about skin disease elsewhere and examine them generally. Fungal nail disease (onychomycosis) is nearly always associated with fungal skin disease (check feet, hands, groin). Nail changes may be the first sign of psoriasis (check scalp, elbows, knees and flexures), lichen planus (check oral mucosa, lower back, scalp, wrists and ankles) or other skin diseases.

Psoriasis may result in haphazard nail pitting, onycholysis, subungual hyperkeratosis, ridging and/ or yellow hypertrophied nail plate.

Eczema is associated with irregular pitting and ridging and paronychia.

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, which are generally self-explanatory.

You are not expected to memorise all of these signs. They are listed for reference only.

Pitting
Eczema
Psoriasis
Alopecia areata
Transverse ridging
Eczema
Psoriasis
Beau's line: single ridge across nail: Acute systemic illness, Trauma
Longitudinal ridging and / or longitudinal splitting
Aging
Trauma
Lichen planus
Darier's disease
Onychomycosis
Psoriasis
Longitudinal groove
Cyst or tumour of matrix
Trauma
Onychogryphosis (thick hard curved nail plate)
Aging
Psoriasis
Trauma
Nail plate thinning
Lichen planus
Trauma
Nail plate crumbling
Psoriasis
Onychomycosis
Distal lamellar splitting; brittle nails
Water/detergent damage
Nail polish removers
Traumatic removal or artificial nails
Distal notching
Darier's disease
Lichen planus
Rough nails
Lichen planus
Twenty Nail Dystrophy
Erosion
SCC
Melanoma
Trauma

Discolouration of nails

Distinguish a discoloured nail bed from a discoloured nail plate.

Yellow
Yellow nail syndrome
Onychomycosis
Psoriasis
Staining from nail enamel
Onycholysis (white or yellow distally,; nail plate lifted off nail bed)
Skin diseases: psoriasis, dermatitis, lichen planus
Idiopathic
Trauma
Systemic disease
Nail infection
Tumour under distal nail plate
Drug photosensitivity
Green
Infection
Brown or black
Staining
Drugs
Infection
Melanocytic naevus
Melanoma
Racial
White (leukonychia)
Vitiligo
Trauma
Hypoalbuminaemia.
Chronic renal failure.
Chemotherapy
Familial
Onychomycosis
Red
Lunula
Darier's disease
Inflammation
Blue
Drugs
Purple/black
Splinter haemorrhage
Haematoma

Cuticle and nail fold abnormalities

The cuticle is an area of keratin joining the skin of the posterior nail fold to the nail plate. Loss of cuticle results in paronychia: an acute or chronic inflammatory reaction involving nail fold (swelling, tenderness, sometimes pus).

Ragged cuticles and telangiectases
Trauma: hang nail
Connective tissue disease
Distal digital infarcts
Vasculitis
Distal subungual hyperkeratosis
Psoriasis
Onychomycosis
Norwegian scabies
Paronychia
Acute
Chronic

Abnormalities of nail shape

Long nail
Uncut
Longitudinal over-curvature
Systemic sclerosis
Sarcoidosis
Clubbing
Chronic lung disease
Cardiac disease
Liver disease
Ulcerative colitis
Collagen vascular disease
Thyrotoxicosis
Koilonychia (thin spoon-shaped nail)
Infants and elderly
Local injury
Iron deficiency anaemia
Systemic retinoids
Pachyonychia (wedge-shaped nails)
Pachyonychia congenita
Idiopathic
Pincer nail (transverse over-curvature)
Epidermal cyst
Idiopathic
In-grown nail
Granulomas are common
Systemic retinoids

Loss of nails

Without scarring
Trauma eg nail biting
Scarring
Trauma eg surgery
Tumour
Erosive lichen planus
Onychomadesis (nail shedding)
Severe systemic disease
Severe lichen planus

Lesions around nails

Common skin lesions that may arise close to nails include:

Viral wart

Corn

Myxoid cyst

Melanocytic naevus

Melanoma

Squamous cell carcinoma
Pyogenic granuloma