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Principles of dermatological practice

Examination of the nails

Created 2008.

Learning objectives

Develop skills in examining the nails and describing:

  • 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.


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.

If the patient presents with a nail problem, it is 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.

Discolouration of nails

Distinguish a discoloured nail bed from a discoloured nail plate.

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).

Abnormalities of nail shape

Loss of nails

Lesions around nails

Common skin lesions that may arise close to nails include:


Describe the clinical signs of onychomycosis.

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Related information


On DermNet NZ:

Information for patients

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