Plantar warts

What they are

The virus enters through tiny breaks in the skin on the bottom of the foot, often in warm, damp places such as pool decks, locker rooms and showers. Because we walk on them, plantar warts grow inward under a layer of thick skin. They are often tender when squeezed from the sides, and may show tiny black dots, which are small blood vessels.

Wart or callus?

A callus is thickened skin from pressure and friction; a wart is an infection. Warts interrupt the normal skin lines, bleed in pinpoints when pared, and hurt more when pinched than when pressed straight on. Calluses keep the skin lines and hurt more with direct pressure. Our article plantar wart or callus? explains how to tell.

Treatment

Treatment is chosen by the size and number of warts, how long they have been there, how painful they are, your age and your health.

• Salicylic acid. In a Cochrane review, salicylic acid was more effective than placebo, though it appeared to work less well on the feet than the hands.^[1] Paring down the thick skin first helps it penetrate, and consistent daily use over weeks is needed. Over-the-counter salicylic acid is a reasonable place to start.^[3]
• Cryotherapy (freezing). Widely used, but a meta-analysis of plantar warts found lower clearance rates with freezing than with several alternative treatments.^[2] Aggressive freezing works better than gentle freezing but causes more pain and blistering.^[1]
• Combined treatment. Salicylic acid with cryotherapy appeared more effective than salicylic acid alone.^[1]
• In-office treatment for stubborn warts: debridement (paring), stronger topical agents, or, for warts that won’t respond, other procedures we discuss with you.

Warts can recur even after successful treatment, because the virus may remain in nearby skin.

What to expect at your visit

We look at the growth closely and, if needed, gently pare the surface: a wart shows pinpoint bleeding from its small blood vessels, while a callus doesn’t. If there is any doubt about what the growth is, we discuss a biopsy. Treatment in the office is usually a series of short visits. Freezing is typically repeated every two to four weeks; in trials, the interval within that range made no difference to how often warts cleared.^[1] Between visits you keep the skin pared and, if we recommend it, apply salicylic acid at home.

Common questions

Should I cut or burn off a wart myself?

No. Filing the thick skin over a wart with a pumice stone or emery board before applying salicylic acid is fine (use it only on the wart, and don’t share it). Cutting deeper, or using sharp tools or heat, risks bleeding, infection and spreading the virus. If you have diabetes, neuropathy or poor circulation, skip home treatment and let us look at it.

Do drugstore freezing kits work as well as freezing in the office?

A review of home care for common foot problems found over-the-counter salicylic acid and freezing products about as effective as liquid nitrogen in the office.^[3] On the feet, though, freezing of any kind clears warts less reliably than on the hands, so a wart that hasn’t improved after a few months of consistent treatment is worth having examined.^[1,2]

Why did my wart come back?

The virus can stay in the skin around a treated wart, so warts sometimes return in the same place or nearby. Finishing the full course and avoiding reinfection both help. A “wart” that keeps returning in exactly the same spot should be re-examined: it may be a callus over a pressure point, which needs a different approach.

Can children be treated?

Yes. Warts are common in children and many clear on their own in time, so we usually start with the gentlest options and avoid painful treatments where we can. See children’s foot care.

Preventing spread

Wear sandals in communal showers and pool areas, don’t share towels or shoes, keep feet dry, and avoid picking at warts.

When to seek care