Both viral warts and keratoderma are benign but can cause problems on the hands. Failing to differentiate them can lead to inappropriate treatment - as occurred with the patient pictured here with palmar keratoderma.
Viral hand warts
- Hyperkeratotic papules with a rough irregular surface
- Size 1mm to 1cm.
- Can occur on any part of the body but most commonly seen on hands and feet
- Usually round but may be elongated if at side of nail
- Usually asymptomatic but may be very tender and can cause cosmetic problems
- Spread by direct or indirect contact. Autoinoculation may occur. (Patient illustrated is an insulin dependent diabetic who has developed these warts at sites of capillary blood sampling)
- Caused by infection with human papilloma virus. Viral particles are found in the basal layer of the epidermis
- Warts are very common – prevalence is about 10%
- Treatment may be with keratolytics such as salicylic acid or lactic acid, or alternatively with cryotherapy.
Palmar keratoderma
- Hyperkeratotic papules
- Linear hyperkeratosis extending up volar aspect of the fingers
- The epidermal thickening may be exacerbated by local trauma (therefore more likely to be worse in manual labourer)
- May be asymptomatic or uncomfortable and often causes cosmetic problems
- Keratodermas are a mixed group of hereditary disorders of keratinization giving rise to epidermal thickening of palms and soles
- Striate keratoderma (illustrated) is autosomal dominant with variable phenotype expression
- Onset usually in early adult life
- Keratolytics are mainstay of therapy but topical and oral retinoids have been used.
- The patient illustrated refused treatment when a correct diagnosis of palmar keratoderma was made- after having a number of ineffective treatments with liquid nitrogen cryotherapy.
Dr Andy Jordan is a GP and hospital practitioner in dermatology in Chesham, Buckinghamshire.
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