Warts are small growths on the skin caused by a virus known as human papillomavirus (HPV). Warts are extremely common: it is estimated that about 25% of the population have a wart at any one time. Luckily, most warts are harmless. However, since they're caused by a virus, warts are very contagious.
Warts can grow anywhere on the skin. There are 6 clinically different types:
- Common warts have a rather bumpy surface and appear most often on the hands and fingers (of children, in particular).
- Flat or plane warts are small, smooth warts appearing in clusters on the back of the hands, face, or legs. These are often difficult to treat.
- Plantar warts are those appearing on the soles of the feet.
- Filiform warts form long, thin projections around the eyes, face, and neck.
- Periungual warts (common in people who bite their nails) occur under and around the fingernails.
- Genital (venereal) warts are those appearing on the genitalia.
Keep in mind that some warts can become cancerous, and some skin cancers can look like warts, so always get them checked by your doctor. Also remember, the sooner a wart is treated, the easier it will be to destroy – so don't procrastinate.
Warts can be caused by 70 different strains of HPV. These viruses exist naturally on human skin, so when a person's immune system is weak (from illness or medications) they are at a higher risk of contracting the virus. Common, plantar, or plane warts can be acquired through something as simple as a cut. Walking barefoot in public areas is also a high-risk activity for contracting warts. Genital warts are more serious and also the most contagious. They are transmitted through direct sexual contact and may take from 1 to 24 months to appear.
Symptoms and Complications
Warts are generally easy to see or feel. People notice them as abnormal growths, bumps, or other odd changes of the skin. More specifically, plantar and genital warts have very distinct symptoms and are more serious types of warts:
- Plantar warts sometimes resemble calluses. They are flat in appearance, deep-rooted in the skin, and can cause pain when you walk. They may be yellow or brown and may also be dotted with tiny grey-black nodules.
- Genital warts are often small and flat. They can be pink, white, or grey. They can also join together, forming cauliflower-like growths. These warts are able to grow on both the external and internal genitalia, including the anus, vagina, urethra, and cervix. Warts in the area around the anus often cause itchiness. Genital warts can also appear in the throat if oral sexual contact occurs with an infected person.
Fortunately, most HPV infections do not become cancerous. However, certain strains of HPV have been associated with the development of cervical cancer, vulvar cancer, anal cancer, and, rarely, cancer of the penis. If and when complications arise, they're often due to genital warts. Warts can also cause a number of problems during pregnancy. They can become bigger and interfere with urination and even cause obstruction during delivery. In rare instances, a baby can also develop warts in the throat (laryngeal papillomatosis) if the mother has genital warts. For this reason, it's important for women to have regular Pap smears, especially those who have experienced HPV infection or genital warts.
Making the Diagnosis
If you notice any abnormal growths, lumps, or skin changes – which may or may not be accompanied by itching, pain, or bleeding - you should make an appointment with your doctor. A quick physical exam by your doctor is usually all that's needed to diagnose warts. The physical exam allows your doctor to distinguish a wart from other skin conditions such as moles, calluses, corns, skin tags, or cancer. To properly diagnose genital warts, your doctor may need to remove a small tissue sample (biopsy). There are also some lab tests available that are useful to diagnose certain strains of HPV and to see whether or not the infection is likely to become cancerous.
Treatment and Prevention
There are plenty of effective treatments for warts, ranging from creams to laser treatment. Your doctor will decide which treatment is best, depending on the type of wart you have.
Common warts: These warts will usually disappear on their own within 2 to 4 years. They often respond to over-the-counter topical preparations such as salicylic acid and lactic acid, which work by peeling off the infected skin. Liquid nitrogen (cryotherapy) may also be used. Cantharidin* (a derivative of the blister beetle) may be used as well.
Plantar warts: These warts may be difficult to get rid of and usually require a stronger solution of salicylic acid. For extremely stubborn plantar warts, your doctor may use laser treatment or liquid nitrogen (cryotherapy).
Genital warts: Treatments for destroying genital warts include the following:*
- trichloroacetic acid (TCA) – one of the most popular treatments for warts; results are usually seen after just 1 or 2 treatments
- podophyllin solution – should not be used by pregnant women, since it can cause birth defects in babies
- 5-fluorouracil cream – this is a strong cream, so follow your doctor's instructions very carefully when using this product; pregnant women should not use this treatment
- interferon injection – this is a treatment in which your doctor injects a chemical called interferon directly into the wart(s)
- imiquimod cream – a cream treatment for genital warts; follow your doctor's instructions
- sinecatechins – an ointment treatment for genital warts; follow your doctor’s instructions
- cryotherapy or electrocautery – freezing or burning the warts
- laser treatment – an effective method for getting rid of particularly stubborn warts
There is a vaccination for genital warts for females aged 9 to 45 years and males aged 9 to 26 years that protects against 9 common types of HPV. HPV, or human papillomavirus, is a sexually transmitted virus that can cause cervical cancer, genital warts, and other health problems. The vaccine protects against the types of HPV that cause about 90% of all genital warts. It also prevents infection with types of HPV that cause 70% of all cervical cancers. There is also another vaccination for HPV available; this vaccination protects against 2 types of HPV that cause 70% of all cervical cancers but does not protect against the strains that cause genital warts.
Apart from genital or plantar warts, many warts will disappear on their own, without any treatment. However, if you find them bothersome, your doctor can prescribe a treatment such as cryotherapy, which involves freezing the warts with liquid nitrogen, or try other medications.
Getting rid of a wart does not actually remove the offending virus. Therefore, to prevent the virus from spreading, it's important to avoid contact with infected items. Try not to touch someone else's warts and don't let bare feet touch unknown moist surfaces. Most importantly, genital warts can be avoided by using condoms during sexual activity. If you're ever diagnosed with genital warts, always complete follow-up exams and tell your partner or previous sexual partners so they can be properly tested and treated.