Warts at The NLM

About Warts

Warts are non-cancerous skin growths caused by a viral infection in the top layer of the skin or mucous membranes. Viruses that cause warts belong to a family called human papillomavirus (or HPV). Warts are usually skin coloured and feel rough to the touch, but can be dark, flat or smooth.

There are several different kinds of warts including :

  • Common wart - Verruca
  • Foot wart
  • Flat wart
  • Genital wart

A common wart or Verruca usually grows around the nails, on the fingers and on the backs of the hands. Foot warts are usually on the soles of the feet and are called plantar warts some people also call them planter warts. Flat warts are smaller and smoother than other warts. They tend to grow in great numbers, 20 to 100 at any one time.

They can occur anywhere, but in children they are most common on the face. Genital wart (also called condyloma) have become a common and worrisome problem in adults. They tend to be small and flat but can be thin and tall. These are soft, not rough and scaly like other warts. Warts probably are passed from person to person, sometimes indirectly.

The time between the first contact and the time that the warts can be seen is often several months. The risk of catching hand, foot and flat warts is small. Warts often disappear without treatment over a period of several months to years. However since warts can be spread to others or new areas of the body it is reasonable to treat most people especially if the warts are bothersome or painful.

Wart Treatments

Most warts can be treated with simple over-the-counter remedies. For those that are resistant to these measures, other types of treatments are effective.

Salicylic acid is a very common and effective over-the-counter treatment, but requires consistent application every day. They best way to use salicylic acid is to first pare the wart with a blade, pumice stone, Emory board, or small scrub brush. Soaking the wart in warm water will aid in the absorption of the medicine. Salicylic acid is applied to the wart and allowed to dry. Normal surrounding skin may be protected with petroleum jelly.

Occluding the treated wart with a band-aid or piece of tape also improves the absorption of the medicine. This procedure should be repeated daily ideally around shower or bath time. Salicylic acid can be found in several forms including a thick oil, or incorporated into an adhesive plaster form.

Cryotherapy is another effective treatment of warts. A provider applies liquid nitrogen as a spray or on a cotton swab to the wart. This freezes and kills the effected cells. The connective tissue is not destroyed; therefore, the lesion usually heals without significant scarring. The human papillomavirus is not killed by cryotherapy and is released into the surrounding tissue allowing the immune system to kill it. A blister typically forms on the site treated, crusts over, and falls off.

Since blisters are painful to walk on, cryotherapy is not a first choice for warts on the bottom of the feet. Other medicines may be applied to warts or injected into them include:

  • Lactic Acid
  • Trichloroacetic Acid (TCA)
  • Formalin
  • Glutaraldehyde
  • Cantharidin
  • Podophyllin
  • Retin-A
  • Bleo-mycin

These treatments should be supervised by a health care provider

The subject of warts, genital warts and plantar warts is a welcomed topic to discuss in the Skincell Forum