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The main nail problems encountered in general practice are trauma, onychomycosis, infection, ingrowing toenails, paronychia and psoriasis. Damage to the nail from trauma or disease results in nail dystrophy. The problem of nail changes due to onychotillomania, be it from excessive nail biting, picking or cleaning, should be suspected from the history and examination. Enquire whether the hands are frequently used in wet work or dirt. Look for associated skin disease (e.g. psoriasis, atopic dermatitis, lichen planus).


Refers to the separation of the nail plate from the underlying nail bed and is a sign rather than a disease. This separation creates a subungual space with an air interface that gathers unwanted debris, such as dirt and keratin.

Self-induced trauma is a common cause from obsessive manipulation, incl. meticulous cleaning and frequent manicuring.

The band of discolouration at the base of the separated nail is usually in a straight line compared with other causes such as psoriasis and tinea. Tinea may be distinguished from other causes by white or yellow streaks or ‘spears’ travelling proximally in the nail.

Greenish discolouration indicates invasion by Pseudomonas pyocyanae or Aspergillus.

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Table N1 Abnormal nails: diagnostic strategy model (modified)

Probability diagnosis

Fungal infection: onychomycosis

Trauma to nail bed

Trauma from biting

Trauma from habit picking




Serious disorders not to be missed


Iron deficiency: koilonychia

Liver disease: leuconychia

Endocarditis: splinter haemorrhages

Chronic kidney failure: white bands, half-and-half nail

Glomus tumour

Bowen disease/SCC

Pitfalls (often missed)

Atopic dermatitis

Lichen planus

Pyogenic granuloma (usually with ingrowing toenails)

Drug effects (e.g. tetracycline)

Pseudomonas infection

Connective tissue disorders (e.g. SLE)

Arsenic (mees stripes)

Management First exclude psoriasis, tinea (check toe webbing) and trauma (check history).


  • Keep nails as short as possible

  • Avoid insertion of sharp objects under nails for cleaning out debris

  • Apply tape (micropore or similar) over free edge for months, until healed

  • Avoid unnecessary soaps and detergents—wear gloves for housework, gardening, etc.

  • Keep hands out of water

  • Use a mild soap and shampoo

  • First-line treatment esp. if mild—vinegar soaks, 10 min bd


  • Exclude fungal infection (clinical tinea pedis)—culture

  • Improve footwear to avoid any rubbing

Pharmaceutical treatment

  • Daily application of an imidazole (e.g. clotrimazole) or terbinafine

  • For Pseudomonas infection soak the nails in vinegar or Milton’s solution and/or apply gentamicin sulfate cream


This is fungal nail infection that mainly affects toenails. The most common form is distal lateral subungual caused by Trichophyton sp. A superficial white onychomycosis with distinct edges is also common. C. albicans and ...

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