Most people have had a wart on their body at some time in their life. Warts are harmless, but most people don’t like the way they look. Warts are extra layers of skin caused by the human papilloma virus (HPV) family. The virus is spread by skin-to-skin contact. Only certain types of HPV cause genital warts and cervical problems. There are more than 150 specific types of HPV; most of them cause the harmless but unsightly warts on other (non-genital) parts of the body.

For questions about genital warts and HPV as it relates to sexually transmitted infections, visit our Human Papilloma Virus page under the Sexual Health category.

What are the different types of warts?

  • Common warts: Where: Usually on fingers, hands, knees, and elbows. What they look like: small hard bumps, darker than other skin, top is rough like cauliflower with black or red-brown dots inside.
  • Plantar warts: Where: on the bottom (plantar) surface of the foot. What they look like: might appear to be a callous, but grow larger than normal and eventually feel similar to walking on small rocks. Looks like a common wart.
  • Filiform warts: Where: often on eyelids, nose, or around the mouth. What they look like: finger-like in shape, skin-colored.
  • Flat warts: Where: in groups on arms, hands, knees, abdomen, or back. What they look like: pinhead sized; flat topped; smoother surface (than other warts); pink, tan, or yellow in color.

How can warts be prevented?

It is easier to catch the virus that causes warts (HPV) when you have a cut or scrape on your skin. Ragged cuticles from dry skin, nail biting or small cuts on hands and feet allow the virus a way into the body. You can get warts from touching a wart on someone’s body. Some people get a wart after touching something that another person’s wart touched, such as a towel. Using slippers or other footwear in public showers may cut down on the chance of transmission. Tools used for paring down warts (eg, nail file, pumice stone, etc.) should not be used on normal skin or nails, and should not be shared with others. Similarly, hair-bearing areas with warts should be shaved with electric razors or not at all.

How long does it take before warts appear after exposure to the virus?

Depending on the health of the immune system that helps fight disease, a person may or may not develop a wart after exposure to HPV. Warts grow slowly, often taking weeks or months to grow to a noticeable size. Most people have been exposed to many strains of non-genital HPV in their childhood. Sometimes the stresses of college suppress the immune system’s ability to keep the virus under control, and a wart may develop many years after initial exposure to the virus.

What are those little black dots in the wart?

Many people believe the black dots are the “seeds of the wart”. This is not true. The black or red-brown dots, that are sometimes visible in the wart, are smothered capillaries (the tiny blood vessels that turn fingertips back to pink after pressure is applied). As the wart virus causes layers of extra skin to pile up, the capillaries get “smothered” and die, leaving the black dots. Digging out the black dots will only cause injury.

How do you treat warts?

About 66% of warts will go away on their own within 2-3 years. If you are impatient, or they are uncomfortable, there are many ways to treat them. There is about a 30% rate of treatment failure with any type of treatment. Treatment causes surface irritation to the skin to stimulate an immune system response to the virus that is causing the wart. Maintaining general good health helps the immune system to function better.

Over the counter treatments containing salicylic acid (Compound W, etc.), when used properly, can be effective. Soaking the wart area in warm water for 10-20 minutes before treatment and using a pumice stone or nail file to remove the excess rough skin in between treatments allows the medication to be more effectively absorbed.

Covering a wart with a small piece of duct tape may help get rid of it although this can take up to 6 weeks. There is lack of agreement about the efficacy of duct tape in the limited studies that have been done.

Office therapies

Cryotherapy (freezing the wart with liquid nitrogen) typically takes two to four treatments which are administered every one to three weeks. Treatments may cause some discomfort but are not usually painful. Some dermatologists use electrosurgery (burning), chemical peels, injections, and laser therapy.

In some cases the wart may be cut out—this is a more drastic treatment and leaves a scar. Some warts are resistant to treatment, and no treatment at this time kills the virus that causes common and plantar warts.

If you’re not sure whether you have a wart or some other skin problem, it’s always a good idea to ask your health care provider for an expert opinion.

Still haven’t found what you’re looking for?

Remember, reading about a condition is no substitute for getting expert advice from a medical professional. If you have symptoms that worry you, schedule an appointment at the Student Health Center.