Plantar warts are small growths that usually appear on your feet’ heels or other weight-bearing areas. This pressure may also cause plantar warts to grow inward beneath a hard, thick layer of skin (callus). Plantar warts are caused by HPV. The virus enters your body through tiny cuts, breaks, or other weak spots on the bottom of your feet.
Dermatologists have many treatments for warts. The procedure used depends on the patient’s age and health. I prefer to cut the callus with a scalpel. Then I use a curette to remove the viral material. Then I use a vascular laser to burn or cauterize tiny blood vessels that feed the virus. Then it cauterizes the base using an ablative laser or chemical TCA. A topical antibiotic is applied, and a special dressing is applied. The patient can walk without any pain immediately.
Plantar warts are small growths that usually appear on your feet’ heels or other weight-bearing areas. Plantar warts are caused by HPV. The virus enters your body through tiny cuts, breaks, or other weak spots on the bottom of your feet. This pressure may also cause plantar warts to grow inward beneath a hard, thick layer of skin (callus). Most plantar warts aren’t a serious health concern and usually go away without treatment eventually. You may want to try self-care treatments or see your doctor have warts removed.
What are the Symptoms of Plantar Warts?
- A small, fleshy, rough, grainy growth (lesion) on the bottom of your foot, usually the base of the toes and forefoot or the heel
- Hard, thickened skin (callus) over a well-defined “spot” on the surface, where a wart has grown inward
- Black pinpoints are commonly called wart seeds but are small, clotted blood vessels.
- A lesion that interrupts the regular lines and ridges in the skin of your foot
- Pain or tenderness when walking or standing
See a Dermatologist for Plantar Wart Treatment
- The lesion is bleeding, painful, or changes in appearance or color
- You’ve tried treating the wart, but it persists, multiplies, or recurs
- Your discomfort interferes with activities
- You also have diabetes or reduced sensation in your feet
- You also have a weakened immune system because of immune-suppressing drugs, HIV/AIDS, or other immune system disorders
- You aren’t sure whether the lesion is a wart
What Causes Plantar Warts?
An infection causes plantar warts with HPV in the outer layer of skin on the soles of your feet. They develop when the virus enters your body through tiny cuts, breaks, or other weak spots on the bottoms of your feet. HPV is prevalent, and more than one hundred kinds of the virus exist. But only a few of them cause warts on the feet. Other types of HPV are more likely to cause warts on other areas of your skin or mucous membranes.
How Can a Virus Transmit?
Each person’s immune system responds differently to HPV. Not everyone who meets it develops warts. Even people in the same family react to the virus differently. The HPV strains that cause plantar warts aren’t highly contagious. So, the virus isn’t easily transmitted by direct contact from one person to another. But it thrives in warm, moist environments. Consequently, you may contact the virus by walking barefoot around swimming pools or locker rooms. If the virus spreads from the first site of infection, more warts may appear.
What are the Risk Factors of Plantar Warts?
Anyone can develop plantar warts, but this type of wart is more likely to affect:
- Children and teenagers
- People with weakened immune systems
- People who have had plantar warts before
- People who walk barefoot where exposure to a wart-causing virus is frequent, such as in locker rooms
What are the Complications of having a Plantar Wart?
When plantar warts cause pain, you may alter your healthy posture or gait — without realizing it. Eventually, this change in standing, walking, or running can cause muscle or joint discomfort.
Is Plantar Wart Preventable?
To reduce your risk of plantar warts:
- Avoid direct contact with warts. This includes your warts. Wash your hands carefully after touching a wart.
- Keep your feet clean and dry. Change your shoes and socks daily.
- Avoid walking barefoot around swimming pools and locker rooms.
- Don’t pick at or scratch warts.
- Don’t use the same emery board, pumice stone, or nail clipper on your warts as you use on your healthy skin and nails.
How Plantar Wart Diagnosed?
In most cases, your doctor can diagnose a plantar wart with one or more of these techniques:
- Examining the lesion
- Paring the lesion with a scalpel and checking for signs of dark, pinpoint dots — tiny clotted blood vessels.
- Removing a small section of the lesion (shave biopsy) and sending it to a laboratory for analysis
Treatment Options for Plantar Warts
Not all warts need treatment as many give minor inconvenience and will resolve spontaneously. In addition, patients may need encouragement to persevere with long-term daily use of more straightforward preparations, and more aggressive therapies, such as cryotherapy or surgery, have potential disadvantages.
Whatever method is used, there will be failures and recurrences. The best clinical guide to curing is restoring normal epidermal texture, including the epidermal ridge pattern where appropriate.
Advice on simple measures to limit the spread of the infection will be appreciated. Plantar warts should be covered with fine plaster strapping, the foot with close-fitting rubber ‘verruca socks,’ pool-side sandals worn at swimming pools, communal baths, or showers. The spread of periungual and perioral warts is often due to biting of nails or periungual skin, and this practice must be strongly discouraged if attempted treatment is to be worthwhile; the use of adhesive strapping after the application of a ‘wart paint’ helps to break the habit.
The most commonly used treatments for warts involve the destruction of the area of the epidermis infected with the virus. Such treatments may involve the application of topical preparations or surgical approaches. In addition, simple domestic hygiene, such as cleaning baths after use and avoidance of shared towels, may be advised.
Other therapies to modify the epidermis’s growth or stimulate an immune response require a topical or a systemic approach. Where treatment trials have been placebo-controlled, a 30% response rate generally is observed for placebo treatment.
Continuous duct tape occlusion of common warts for up to 2 months compared favorably with cryotherapy every 2–3 weeks in children]. Still, placebo-controlled trials have not confirmed any significant effect in either adults or children].
The keratolytic effect of salicylic acid helps to reduce the thickness of warts and may stimulate an inflammatory response. A preparation containing 12–26% salicylic acid, possibly with additional lactic acid, in a quick-drying collodion or acrylate base is the treatment of the first choice for standard and plantar warts.
Daily use in a comparative study for three months achieved cure rates of 67% for hand warts, 84% for simple plantar warts, and 45% for mosaic plantar warts, comparing favorably with other methods, including liquid nitrogen. A review of six placebo-controlled trials confirmed this impression, with 75% cured compared to 48% of placebo-treated patients.
Removing surface keratin and the remnants of the previous application by gentle use of a pumice stone, emery board, or foot file is a helpful preliminary in all warts and essential in very hyperkeratotic plantar warts. However, overenthusiastic abrasion is an expected, if understandable, mistake, which may enhance the spread of the virus by injection into the adjacent skin. It is conceivable that warts’ abrasion may help stimulate an immune response].
Accurate application of a salicylic acid preparation, avoiding normal skin, may require a fine applicator such as a sharpened matchstick or a cocktail stick and minimize subsequent local discomfort. After drying, a whitish deposit remains.
Penetration into thick keratin, as on the sole, is enhanced by adhesive plaster occlusion, promoting maceration of the keratin layer and reducing barrier function. Occlusion can improve the response rate for treatment with salicylic acid.
Collodion contains colophony, which may cause allergic contact dermatitis. These preparations are not suitable for anogenital warts. They can be particularly irritant on facial skin, though especially careful application or the use of weaker formulations, such as 4% salicylic acid in flexible collodion may be successful. Long-standing warts have been observed to disappear if the patient perseveres with this inadvertent immunotherapy, but the discomfort is usually too great for this approach to be regularly helpful.
Adhesive plaster containing 40% salicylic acid is helpful for plantar warts. It is applied daily, cut to the shape of the wart or group of warts, and held in place by plain adhesive plaster. The regular use of salicylic acid preparations on warts may need to be continued for at least three months and often longer.
The virucidal properties of glutaraldehyde can be used in wart treatment. A preparation of 20% glutaraldehyde in an aqueous solution produced a 72% cure rate. Still, the glutaraldehyde dries into the skin without a surface deposit that could be rubbed off, making it a valuable application for warts on the feet.
Podophyllin and podophyllotoxin.
Podophyllin is a plant-derived resin containing several cytotoxic compounds in unpredictable ratios. The most active of these is podophyllotoxin. The crude resin and purified podophyllotoxin are used to treat anogenital warts, as they are more effective on mucosal than skin surfaces. For both penile and vulval warts, the patient can perform self-application of podophyllotoxin in either solution or cream formulation and give a higher remission rate than the use of podophyllin.
Podophyllin resin is not used so commonly now, but treatment should be under professional supervision. A solution of 10–25% in a compound tincture of benzoin is applied accurately to the area and then allowed to dry for a few minutes. The resin should be thoroughly washed off after 4 hours, though the time can be cautiously increased if the treatment is well tolerated. Applications are repeated weekly or more often.
Podophyllin is contraindicated in pregnancy. It should not be used on exceptionally large or bleeding areas, where its application has been followed by intrauterine death
Podophyllin and podophyllotoxin are generally ineffective if simply applied to warts of other types due to the lack of penetration of the keratin layer. However, they can be used with caution under occlusion  or in combination with salicylic acid. Although clearance rates may be as high as 80–95%, acute pain can occur with intense local inflammation.
Soaks or compresses of 2–3% formalin in water (formalin is about 37% formaldehyde in water) may be effective for plantar warts but is time-consuming and difficult to limit to affected skin. The affected area must be soaked in the solution for 15–20 min daily, using soft paraffin as a barrier application to protect more sensitive skin.
Caustic such as TCA, silver nitrate, cantharidin, phenol, and other highly irritant chemicals can be used with the effect but may cause painful reactions. In treating genital warts, cryotherapy is slightly more effective than trichloroacetic acid alone.
This treatment topically may be tried in-plane warts, but the best results are claimed for higher than usual concentrations, and irritation is common
Systemic or topical aminolaevulinic acid can be taken up by dividing cells, metabolized to protoporphyrin, and then photoactivated to produce a damaging effect on the cell. The treatment may need to be repeated two or three times but can be limited by pain .
Carbon dioxide, snow, and liquid nitrogen can produce cold thermal damage to the skin. Liquid nitrogen is commonly used in hospital practice, applied either by a cotton wool bud or from a cry spray. The response to treatment with cryotherapy is comparable to that achieved with salicylic acid . After three months, treatment repeated every three weeks gives a 30–70% cure rate for hand warts.
Excision is usually avoided since scarring is inevitable, and recurrences of the wart in the scar are frequent. However, good results have been obtained by snipping out perianal warts after sub-skin injection of adrenaline 1: 300000 in physiological saline under general or local anesthesia.
Curettage can also be effective as a treatment for fi aliform warts. Curettage and cautery may be used for painful or resistant warts but carry a risk of scarring.
Topical application of local anesthetic cream to the vulva for 10 min numbed the area in over 90% of cases, but otherwise, and for skin, local anesthetic injection or even general anesthesia would be required. A technique of blunt dissection has been advocated for plantar warts.
More frequent treatments may improve responses, although they induce more pain, and longer intervals are less effective. If this fails, or when a wart is particularly painful or deep, or both, as may occur over a bony prominence on foot, more prolonged application, typically up to 30 s, perhaps repeated after thawing, may be used to achieve a more significant destructive effect at the
cost of significantly greater blistering and pain. For such treatment, local or even general anesthesia may be considered. The common practice of dipping cotton buds for different patients into an ordinary flask containing the liquid nitrogen may risk cross-infection.
The main disadvantage of freezing is pain. This is unpredictable and surprisingly variable between patients. Still, in some cases, especially with longer freezing times, it may be severe and persist for many hours or even a few days.
Oral aspirin and solid topical steroids may help. Swelling of the treated area and the surrounding skin begins within minutes, and where tissues are lax as in the periorbital area, it may be dramatic. A blister, sometimes hemorrhagic, may ensue within a day or two. After the usual short freezing times, the reaction will likely be resolved within 2–3 weeks. Scarring is unlikely with freezing times under 30 s.
Occasionally, damage to underlying tissues may result in a tendon or the nail matrix, and excessive freezing times should be avoided over nerves, for example, on the sides of the fingers. Depigmentation may be a significant cosmetic disadvantage in patients with darkly pigmented skin.
The carbon dioxide laser has been used to treat various forms of wart, both skin and mucosal. It can effectively eradicate some difficult warts, such as periungual and subungual warts that have been unresponsive to other treatments.
Clearance of skin warts at 12 months is 55–70%. Carbon dioxide laser therapy is well-tolerated but, as with cryotherapy, surgery, or other destructive methods, can cause significant postoperative pain, scarring, and temporary loss of function.
Hypertrophic scarring may be exacerbated by concomitant ciclosporin treatment. An infectious virus can be detected in the plume during carbon dioxide laser used, so an operator mask and air extraction system are advised.
The pulsed dye laser produces less scarring and has been used to treat warts with cure rates of approximately 50–70%, using a minimum of two treatments. It appears comparable to other treatments such as cryotherapy. Other lasers such as the Er: YAG and the Nd: YAG can also be used
Different routes have administered different interferons (IFNs) to patients with refractory warts. These studies are seldom directly comparable, and the use of interferons in warts is still experimental. For the most part, interferon use has been disappointing.
Topical immunomodulation with imiquimod 5% cream is licensed to treat genital warts. Butchers’ warts, filiform facial, and plane warts may all respond, and immunosuppression does not appear to block the therapeutic effect.
Skin warts have also responded to imiquimod treatment, although poor penetration through the skin surface may necessitate twice daily application for up to 24 weeks, in combination with occlusion or salicylic acid to achieve valuable results.
The treatment can cause irritation, discomfort, and occasionally erosion at the point of application with a small risk of causing vitiligo-like depigmentation.
Cimetidine. Results from oral cimetidine in wart treatment in adults have been conflicting. Cimetidine produces more significant benefits in children. It is combined treatment with levamisole may enhance the effect.
Zinc. Oral zinc has a mild effect on the immune system. One study of oral zinc sulfate (10 mg/kg/day) reported an 87% cure rate of warts, but there was a high incidence of side effects leading to the discontinuation of therapy. In a double-blind trial, zinc sulfate as a 10% aqueous solution produced a cure rate of 86% for plane warts.
By reducing epidermal proliferation, oral retinoids can help to debulk warts, although the infection may persist, making relapse likely.
Hyperkeratotic warts in otherwise healthy patients can respond to oral retinoid therapy [101,102]. This effect may be temporarily helpful, perhaps in relieving pain or disability due to exceptionally hyperkeratotic warts or in facilitating the use of other treatments.
Doses of this cytotoxic agent are given in units of milligrams; 1 mg contains 1500 to 2000 U. Protocols vary, but typically bleomycin sulfate 0.25–1 mg/mL is injected up to three times to a maximum total dose of 4 mg.
Injections are into the wart itself, confirmed by observing blanching in the lesion, the volume per injected lesion ranging between 0.2 and 1.0 mL. Injections are excruciating, and preceding, or concurrent local anesthesia should be considered, especially for sensitive sites such as fingers and soles.
A hemorrhagic eschar develops; 2–3 weeks later, it is pared down if it has not detached spontaneously. Cure rates for previously refractory warts are reported to be between 30 and 100%
Local heat. Repeated raising of the temperature of wart-affected skin to a maximally tolerated level of about 50°C is reported to induce wart clearance. The Nd: YAG laser can be used to produce a similar effect.
Many myths and studies claiming that warts can be effectively treated by suggestion or ‘magic’ have been inadequately controlled for spontaneous regression. Formal hypnosis, however, was reported. Children appear to have a higher rate of success than adults.
The many treatments listed above indicate the lack of an ideal method for eliminating warts.
Prophylactic vaccination to prevent primary infection with HPV types 6, 11, 16, and 18 has recently become available and is hoped, over the years, to lead to a gradual reduction in the number of cases of anogenital malignancies and genital warts. The effects are type-specific.
Other treatments. Green tea extract in topical preparation has been reported to have a beneficial effect in treating genital warts.