Nail abnormalities

Question 1

Probability diagnosis

Answer 1

Fungal infection: onychomycosis

Onycholysis:

• trauma to nail bed
• trauma from biting
• trauma from habit picking

Onychogryphosis

Paronychia

Psoriasis

Question 2

Serious disorders not to be missed

Answer 2

Melanoma

Iron deficiency: koilonychia

Liver disease: leuconychia

Endocarditis: splinter haemorrhages

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

Glomus tumour

Bowen disorder/squamous cell carcinoma

Question 3

Pitfalls (often missed)

Answer 3

Atopic dermatitis (pitted nails)

Lichen planus

Pyogenic granuloma (usually with ingrowing toenails)

Drug effects (e.g. tetracycline)

Pseudomonas infection

Connective tissue disorders (e.g. SLE)

Arsenic (Mees stripes)

Question 4

Is the patient trying to tell me something?

Answer 4

Consider onychotillomania, where pts pick and self-mutilate their nails, resulting in parallel transverse grooves (washboard deformity or habit-tic nails).

Question 5

Key history

Answer 5

Hx of severe stress or illness and possible onychotillomania, be it excessive nail biting, picking or cleaning.

Ask whether the hands are frequently in wet work e.g.

• dishwashing
• soaps
• detergents
• or dirt.

Question 6

Key examination

Answer 6

Careful examination of nails:

Look for associated skin disease, e.g.

• psoriasis
• atopic dermatitis
• tinea pedis
• lichen planus

Question 7

Key investigations

Answer 7

Nail clippings for culture and histology

FBE and ESR

Consider LFTs and CXR

Question 8

Diagnostic tips

Answer 8

Clubbing is an abnormality of the fingertips rather than nails.

Crumbly white nails are not always caused by fungus.

Skin disorders that can involve nails include;

• atopic dermatitis
• psoriasis
• epidermolysis bullosa
• exfoliative dermatitis
• lichen planus.