Warts are small, benign growths caused by a viral infection of the skin or mucous membrane. The virus infects the surface layer. The viruses that cause warts are members of the human papilloma virus (HPV) family. Warts are not cancerous but some strains of HPV, usually not associated with warts, have been linked with cancer formation. Warts are contagious from person to person and from one area of the body to another on the same person.
When skin warts appear, it can seem as if the harmless growths came out of nowhere.
But common warts are actually an infection in the top layer of skin, caused by viruses in the human papillomavirus, or HPV, family. When the virus invades this outer layer of skin, usually through a tiny scratch, it causes rapid growth of cells on the outer layer of skin – creating the wart.
“HPV is ubiquitous,” says dermatologist Conway Huang, MD, an associate professor of dermatologic surgery and cutaneous laser surgery at the University of Alabama at Birmingham. “We all come in contact with it,” throughout our lives, such as when shaking hands, turning doorknobs, or typing on keyboards.
Scientists have identified more than 100 unique types of the virus. And most people will have at least one common wart at some time in their lives, usually on their hands.
Certain forms of the virus are more likely to cause skin warts on the hands. Other forms of HPV are more likely to cause genital warts, although some strains of the virus can cause both.
Warts can affect any area on the skin and mucous membranes. The HPV virus infects the epithelium, and systemic dissemination of the virus does not occur. Viral replication occurs in differentiated epithelial cells in the upper level of the epidermis; however, viral particles can be found in the basal layer.
In women, genital warts can grow on the vulva, the walls of the vagina, the area between the external genitals and the anus, the anal canal, and the cervix. In men, they may occur on the tip or shaft of the penis, the scrotum, or the anus. Genital warts can also develop in the mouth or throat of a person who has had oral sexual contact with an infected person.
The signs and symptoms of genital warts include:
- Small, flesh-colored or gray swellings in your genital area
- Several warts close together that take on a cauliflower shape
- Itching or discomfort in your genital area
- Bleeding with intercourse
Often, genital warts may be so small and flat that they can’t be seen with the naked eye. Sometimes, however, genital warts may multiply into large clusters.
Patients who notice warts in their genital area should see a doctor. The doctor may be able to diagnose the warts with a simple examination. If the warts are small, the doctor may put a vinegar-like liquid on the skin, which makes the warts turn white and easier to see, and then use a magnifying glass to look for them.
If your warts aren’t causing discomfort, you may not need treatment. But if your symptoms include itching, burning and pain, or if visible warts are causing emotional distress, your doctor can help you clear an outbreak with medications or surgery. However, the lesions are likely to come back after treatment.
Genital wart treatments that can be applied directly to your skin include:
- Imiquimod (Aldara, Zyclara). This cream appears to boost your immune system’s ability to fight genital warts. Avoid sexual contact while the cream is on your skin. It may weaken condoms and diaphragms and may irritate your partner’s skin.
One possible side effect is redness of the skin. Other side effects may include blisters, body aches or pain, cough, rashes, and fatigue.
- Podophyllin and podofilox (Condylox). Podophyllin is a plant-based resin that destroys genital wart tissue. Your doctor must apply this solution. Podofilox contains the same active compound, but can be safely applied by you at home.
Your doctor may want to administer the first application of podofilox, and will recommend precautionary steps to prevent the medication from irritating surrounding skin. Never apply podofilox internally. Additionally, this medication isn’t recommended for use during pregnancy. Side effects can include mild skin irritation, sores or pain.
- Trichloroacetic acid (TCA). This chemical treatment burns off genital warts. TCA must always be applied by a doctor. Side effects can include mild skin irritation, sores or pain.
Don’t try to treat genital warts with over-the-counter wart removers. These medications aren’t intended for use in the moist tissues of the genital area. Using over-the-counter medications for this purpose can cause even more pain and irritation.
You may need surgery to remove larger warts, warts that don’t respond to medications, or — if you’re pregnant — warts that your baby may be exposed to during delivery. Surgical options include:
- Freezing with liquid nitrogen (cryotherapy). Freezing works by causing a blister to form around your wart. As your skin heals, the lesions slough off, allowing new skin to appear. You may need repeated cryotherapy treatments. The main side effects include pain and swelling.
- Electrocautery. This procedure uses an electrical current to burn off warts. You may have some pain and swelling after the procedure.
- Surgical excision. Your doctor may use special tools to cut off warts. You’ll need local or general anesthesia for this treatment, and you may have some pain afterward.
- Laser treatments. This approach, which uses an intense beam of light, can be expensive and is usually reserved for very extensive and tough-to-treat warts. Side effects can include scarring and pain.