Examination of the nails

Learning objectives
Introduction
Abnormalities of the nail plate surface
Discolouration of nails
Cuticle and nail fold abnormalities
Abnormalities of nail shape
Loss of nails
Lesions around nails
Activity

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.

Introduction

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 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.

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 Ageing Trauma Lichen planus Darier's disease Onychomycosis Psoriasis
Longitudinal groove Cyst or tumour of matrix Trauma
Onychogryphosis (thick hard curved nail plate) Ageing 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 & 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 & 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 e.g. nail biting
Scarring Trauma e.g. 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

Activity

Describe the clinical signs of onychomycosis.

 

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