Definition

Plantar warts are growths on the soles of the feet. They are often mistaken for corns or calluses. They grow in clusters and are usually flat. A plantar wart can often be distinguished by numerous black dots visible on their surfaces.

Although plantar warts are generally harmless, their location beneath the feet can make them very tender. They also have a tendency to spread locally to other sites on the foot and elsewhere.

Causes

Plantar warts are caused by the human papillomavirus (HPV). It can be contracted by walking barefoot on unsanitary surfaces. Touching and scratching can cause the virus to spread.

Risk Factors

Plantar warts are more common in children and teens. Other factors that may increase your chance of plantar warts include:

• Exposing your feet to unsanitary surfaces
• Suppressed immune system due to:
  • HIV infection
  • Lymphoma
  • Immunosuppressive drugs
• Skin inflammation— eczema

Symptoms

Plantar warts may cause:

• Hard, flat growths on the soles of the feet
• Heaped-up calluses surrounding the wart surfaces
• Pain in the area of the warts

Diagnosis

The doctor will ask about your symptoms and medical history. Your feet will be examined. Some doctors may wish to refer difficult cases to specialists. Podiatrists focus on foot disorders. Dermatologists focus on skin disorders.

Treatment

There are many over-the-counter products available to treat warts. These therapies often contain a mild acid. You can usually apply them when a wart first appears.

Another popular and less expensive treatment is using duct tape to cover a wart for a week at a time. This is also done with weekly “sanding” of the wart with a pumice stone.

You should see a doctor:

• For recurrent warts
• For those that fail to respond to initial treatment
• When over-the-counter therapies are not well-tolerated
• When the diagnosis is unclear

After confirming the diagnosis of plantar warts, the doctor may use one or more of the following:

• Cryotherapy—freezing the warts to kill the virus
• Laser treatment—using a laser to kill the virus and destroy wart tissue
• Electrocautery treatment—burning the wart
• Hyperthermia treatment—applying heat to kill the virus
• Surgical removal—cutting out the warts (with anesthetic)
• Immune therapy—application of substances that stimulate the immune system’s response to the wart-causing virus

Prevention

The best ways to prevent plantar warts is to keep your feet from coming into contact with the virus that causes them. Ways to do this include:

• Avoid walking barefoot, except on sandy beaches.
• Wear plastic sandals when showering in public bathrooms.
• Change your shoes and socks daily.
• Keep your feet clean and dry.
• Avoid direct contact with warts, either from other people or from other parts of the body.

In addition, periodically checking for warts on your child’s feet may help prevent them from becoming larger and painful.

American Podiatric Medical Association http://www.apma.org

Canadian Podiatric Medical Association http://www.podiatrycanada.org

Plantar wart. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated March 13, 2013. Accessed September 4, 2014.

Plantar warts. Mayo Clinic website. Available at:
http://www.mayoclinic.org/diseases-conditions/plantar-warts/basics/definition/con-20025706
Updated May 22, 2014. Accessed September 4, 2014.

Warts. American Podiatric Medical Association website. Available at:
http://www.apma.org/learn/FootHealth.cfm?ItemNumber=989
Accessed September 4, 2014.

7/30/2010 DynaMed’s Systematic Literature Surveillance
http://www.ebscohost.com/dynamed:
Huo W, Gao XH, Sun XP, et al. Local hyperthermia at 44 degrees C for the treatment of plantar warts: a randomized, patient-blinded, placebo-controlled trial. J Infect Dis. 2010;201(8):1169-1172.