Warts are small, usually painless growths on the skin caused by a virus. They are generally harmless. However, warts can be disfiguring and embarrassing, and occasionally they itch or hurt (particularly on the feet).

The different types of warts include:

• Common warts usually appear on the hands, but can appear anywhere.
• Flat warts are generally found on the face and forehead. They are common in children, less so in teens, and rare in adults.
• Genital warts are usually found on the genitals, in the pubic area, and in the area between the thighs, but they can also appear inside the vagina and anal canal.
• Plantar warts are found on the soles of the feet.
• Subungual and periungual warts appear under and around the fingernails or toenails.

The typical wart is a raised round or oval growth on the skin with a rough surface. Compared with the surrounding normal skin, warts may appear light, dark, or black (rare). Most adults are familiar with the look of a typical wart and have little trouble recognizing them. Unusual warts with smooth surfaces or flat warts in children may be more difficult for parents to recognize.

Common warts tend to cause no discomfort unless they are in areas of repeated friction or pressure. Plantar warts, for example, can become extremely painful. Large numbers of plantar warts on the foot may cause difficulty running and even walking.

Warts around and under your nails are much more difficult to cure than warts elsewhere.

Some warts will disappear without treatment, although it can sometimes take a couple of years. Treated or not, warts that go away often reappear. Genital warts are contagious, while common, flat, and plantar warts are much less likely to spread from person to person. All warts can spread from one part of your own body to another.

Because people generally consider warts unsightly and there is often a social stigma, treatment is often sought.

• Abnormally dark or light skin surrounding the lesion
• Numerous small, smooth, flat (pinhead sized) lesions on forehead, cheeks, arms, or legs
• Rough growths around or under fingernails or toenails
• Rough, round, or oval lesions on soles of feet -- flat to slightly raised -- painful to pressure
• Small, hard, flat or raised skin lesion or lump

Warts can generally be diagnosed simply by their location and appearance. Your doctor may want to cut into a wart (called a biopsy) to confirm that it is not a corn, callous, or other similar-appearing growth.

Over-the-counter medications can remove warts. These are applied to the wart every day for several weeks. DO NOT use these medications on your face or genitals. It helps to file the wart down when damp (for example, after a bath or shower) before applying these medications.

Special cushions are available at drugstores for plantar warts. These pads help relieve any pressure and pain from the warts.

Stronger (prescription) medications may be required for removal of persistent warts. Surgical removal or removal by freezing (cryotherapy), burning (electrocautery), or laser treatment may be needed.

Immunotherapy, done by injecting a substance that causes an allergic reaction, may also be considered by your doctor.

A vaccine called Gardasil prevents infection against the strains of viruses that often cause genital warts and cervical cancer in women.

DO NOT attempt to remove a wart yourself by burning, cutting, tearing, picking, or any other method.

Warts are generally harmless growths that often go away on their own within two years. They can be contagious, but transmission from person to person is uncommon. Warts may be unsightly or cause discomfort, especially on the feet.

• Spread of warts
• Return of warts that disappeared
• Minor scar formation if the wart is removed
• Formation of keloids after removal

Call for an appointment with your doctor if:

• There are signs of infection (red streaking, pus, discharge, or fever) or bleeding. Warts can bleed a little, but if bleeding is significant or not easily stopped by light pressure, see a doctor.
• The wart does not respond to self-care and you want it removed.
• You have pain associated with the wart.
• You have anal or genital warts.
• You have diabetes or a weakened immune system (for example, HIV) and have developed warts.
• There is any change in the color or appearance of the wart.

• Avoid direct skin contact with a wart on someone else.
• After filing your wart, wash the file carefully since you can spread the virus to other parts of your body.
• After touching any of your warts, wash your hands carefully.

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Habif TP. Clinical Dermatology. 4th ed. St. Louis, Mo: Mosby; 2004:368-378.

Kasper D, Braunwald E, Fauci A, et al. Harrison's Principals of Internal Medicine. 16th edition [online version]. New York, NY: McGraw Hill; 2005.

Gibbs S, et al. Topical treatments for cutaneous warts. Cochrane Database Syst Rev. 2006;(3):CD001781.

Habif, TP. Clinical Dermatology. Philadelphia, Pa: Mosby Elsevier; 2004:chap 12.