Plantar warts

What is a plantar wart, and how common is it?

A plantar wart (a verruca, or verruca plantaris) is a thickened patch of skin on the sole of the foot, caused by infection with human papillomavirus, or HPV¹. It's usually harmless and tends to go away by itself in time². Warts of all kinds are common, with about 7–12% of people affected³.

A plantar wart can appear on the sole, heel or toes. Your body weight pushes it into the skin, so it's usually flat rather than raised, and it may hurt when you walk⁴.

What causes plantar warts, and who gets them?

Plantar warts are caused by HPV infecting the skin of the sole¹. Warts can occur at any age³.

The virus spreads through direct skin contact, or from contaminated surfaces such as swimming pools and gyms⁴. It's more likely to spread when skin is wet or damaged⁵. It can help to take extra care with cuts, cracks and wet skin where surfaces are shared.

What does a plantar wart feel like, and how is it diagnosed?

A plantar wart often looks like a white area of skin with one or more tiny black dots in the centre⁴. The dots are small blood vessels, and they're easiest to see once hard skin is pared away⁶. The normal lines of your skin are also broken up across the wart⁷. Verrucas are more likely than other warts to hurt, a bit like standing on a needle⁵.

Diagnosis is mostly by a podiatrist or doctor looking at the foot⁸. Callus and other skin conditions can look similar⁸, so a podiatrist may look closely before treating.

What helps first?

If a wart isn't bothering you, waiting is a reasonable option. Many warts clear without treatment: in primary schoolchildren, about half were wart-free within a year⁹.

The usual first step is wart paint or gel containing salicylic acid or lactic acid. You apply it daily, and it can take many weeks to work⁴. Salicylic acid is the usual first-line treatment you can buy without a prescription¹⁰. A pharmacist can explain how to use it safely¹¹.

A podiatrist or GP can also offer cryotherapy (freezing the wart). It can cause blistering, scarring, delayed healing and changes in skin colour³¹². Using acid paint and freezing together did better than either alone¹³.

Be realistic about results: cure rates for plantar warts are modest, and no treatment works for everyone¹⁴. The evidence for freezing is mixed, though firmer freezing seems to work better than gentle freezing¹³.

What helps if that isn't enough?

If paint and freezing haven't worked after a fair trial, it's better to move on than to repeat the same treatment. A podiatrist or GP can discuss other options, including injections into the wart (such as vitamin D3, Candida antigen or bleomycin), laser, and prescription antiviral or chemotherapy-type medicines. Reviews report that these can work better than freezing¹²¹¹⁴. Comparisons of the injection treatments haven't found a clear winner¹⁰, so the choice is best made with your clinician.

A painful wart that has lasted at least two years and hasn't responded to paint and freezing is a reason to be referred on⁶.

How long does a plantar wart last, and will it come back?

How long a wart takes to go varies from person to person. Plantar warts often come back after treatment³. Freezing is often repeated every three weeks, for up to 10 treatments⁶. If a wart returns, it's worth going back early rather than waiting it out.

Smoking is linked with warts coming back after successful treatment¹⁵. If you smoke, your GP or pharmacist can help with cutting down or quitting.