Source Knol: Genital Warts
by Daniela Carusi, MD, MSc
Instructor of Obstetrics, Gynecology & Reproductive Biology at Brigham & Women's Hospital & Harvard Medical School, Boston
Genital warts, like warts that occurr on the hands and feet, develop when a group of skin cells divides excessively, producing a raised, firm bump. They usually measure from one to a few millimeters, though occasionally they can cover a wide area of the genitalia. When very large they can take on a cauliflower-like appearance. In women the lesions are usually found at the base of the vagina or on the labia, though they can also occur within the vagina and on the cervix. In men, they can occur on the penile shaft or on the glans (tip) of the penis. In either gender they may occur in the anal area, particularly in those who receive anal intercourse.
Genital warts often cause no symptoms, and may be found incidentally during a physical exam. Larger warts may cause discomfort, itching, burning, or vaginal discharge in women. Very large warts may actually obstruct the vagina, urethra, or anus, or may occasionally cause skin cracking or bleeding.
All warts are caused by an infection with the human papilloma virus, or HPV. HPV is the most common sexually transmitted virus in the United States, affecting an estimated 80% of sexually active adults at some time. Most people who acquire HPV have no symptoms, and it is usually impossible to know when an individual was infected. HPV is transmitted sexually, through skin-to-skin or oral-skin contact. An individual may transmit the virus even when there is no visible wart.
Well over 100 strains of the virus have been identified, which differ in the location of infection (in terms of genital or non-genital infection) and their tendency to cause cancers. HPV types 6 and 11 cause most genital warts but do not cause cancers, and thus they are considered “low-risk” types. Individuals may be infected by multiple virus types, so those who have non-cancerous warts may also have a strain of “high-risk,” cancer-causing HPV. Individuals with warts should have regular exams, and women should have cervical cancer screening according to standard guidelines.
Risk factors for HPV infection include young age (with the highest incidence among women 20 to 24 years old), history of multiple sexual partners, and a weakened immune system. Warts may occur from weeks to months after the initial infection, and in general the viral infection will clear within a year of acquisition. Those who contract HPV at an older age and those with weakened immune systems are less likely to eliminate the infection.
How are Genital Warts Diagnosed?
Trained health care providers can identify warts by inspecting the genitalia. Usually no other testing is necessary. The warts are firm, raised, flesh-colored or pale bumps. They often occur in clusters or as scattered small lesions. They must be distinguished from micropapillomatosis, which are normal, fine bumps on the genitalia. Genital warts will have multiple tiny lobules coming from a single base, while micropapillomatosis has only one tiny bump that arises from a single base.
The picture on the right shows a few small genital warts on a female patient. Two vulvar and one peri-anal wart are indicated by the arrows. An image of more extensive warts can be seen by clicking the following link : http://www.2womenshealth.com/images/gernital_warts.jpg.
If the skin lesion has an unusual appearance, such as an unusual color or texture, or if it appears as an open or bleeding sore, then it should be biopsied. This involves giving numbing medicine to the skin and then removing a small piece of the lesion, which can be accomplished in a medical office. This should be done to exclude the possibility of a cancer or pre-cancer. A biopsy should also be performed if the wart does not respond to routine treatment or if the patient has a weakened immune system (and would therefore be more susceptible to cancers).
How are Genital Warts Treated?
Genital wart treatment is aimed at relieving a patient’s symptoms. Small warts found on physical exam may be left alone if they do not bother the patient. Approximately 20-30% of these lesions will resolve on their own
Genital warts can be treated with medications or by physically removing the lesions. Treatments that eliminate the warts may not remove the virus. Consequently, the lesions will commonly recur after successful treatment, and individuals may still transmit the virus even when the warts are no longer present. Currently there is no medical cure available for HPV, although as noted, many individuals will clear the infection on their own a few years after exposure.
Medical treatments for genital warts work in one of two ways: they either destroy the cells that make up the wart, or they activate the patient’s immune system to clear the lesion. Some medical treatments can be used by the patient at home, while others require application by a medical provider. There are only a few studies comparing one type of therapy to another, and thus the treatment should be selected based on availability, cost, and convenience. Any type of medical therapy usually requires multiple applications.
Common Medical Therapies:
· Trichloroacetic acid (TCA): This acid solution is applied directly to the wart with a cotton swab, and works by destroying cell proteins. Care must be taken to avoid touching the healthy skin, and it must be applied by a health care professional. Applications are usually performed weekly until the warts resolve, usually within 4-6 weeks.
· Podophyllin: This medication works by blocking cell division so that the wart can no longer grow. It is similarly applied by a health care provider on a weekly basis, and should be washed off a few hours later. It should not be used within the vagina or on a woman’s cervix, as it can cause burns.
· Podophyllotoxin (Condylox®): This medication is derived from podophyllin, but can be applied by the patient at home. Twice daily for 3 consecutive days the patient applies the drug to the warts, and then takes 4 days off of treatment. This cycle can be repeated weekly for up to 4 weeks. A study comparing this medication to podophyllin showed that the home therapy had better results.
· Imiquimod (Aldara®): This medication works by activating an individual’s immune system in the area of the wart. The immune cells then destroy the wart tissue. The patient applies a cream directly to the wart three times per week, washing off the medication 6 – 10 hours later. This can be done for up to 16 weeks. The treatment normally causes some redness and inflammation at the treatment site, but these symptoms will resolve.
Uncommon Medical Therapies
· 5-Fluorouracil: This is another medication that blocks cell division, and can be injected at the base of the wart. This is performed weekly for up to 6 weeks. Patients may notice pain and ulceration at the injection site.
· Interferon: This medication induces the patient’s immune system, and is also injected at the base of the wart. It may be given as an intramuscular injection as well. In either case it may cause pain and flu-like symptoms, and is not very well tolerated by patients.
Genital warts may be physically removed by freezing, cutting them off with a knife or scissors, or destroying them with laser or ultrasound. As with medical therapy, this treatment may not remove the underlying virus. These physical treatments are often performed when medical treatments fail, or when the warts are very large.
· Freezing/ Cryotherapy: Wart tissue may be destroyed by freezing it with liquid nitrogen or nitrous oxide. This is performed in a medical office, and may require multiple treatments on a weekly basis. It is usually reserved for smaller lesions.
· Surgical removal: Warts may be removed by cutting them off at their base. This may be desirable with very large lesions, or in situations where a biopsy is needed to exclude a pre-cancer or cancer. Depending on the size of the warts, this procedure requires local (numbing medicine given only to the area involved) or general (patient goes to sleep) anesthesia, and the procedure may produce some pain or scarring.
· Laser therapy: A trained provider may destroy the wart tissue with a laser. This must be done in an operating room with anesthesia, and can also produce pain and scarring after the procedure. It is often the treatment of choice with very large lesions.
· Ultrasound aspiration: This is a specialized treatment that destroys the wart tissue with an ultrasonic aspirator. It also must be performed in an operating room by a trained clinician.
Surgical removal, laser, and ultrasound treatment should ideally remove the wart without damaging the underlying skin. This will minimize scarring later on. Follow-up care involves soaking the treated area, and often applying antibacterial creams.
Is it Safe to Have Sex during Treatment for Genital Warts?
This is a common concern, especially as a patient may need many weeks of treatment. In general, contact should be avoided while a medication is on the skin, or if the patient is experiencing pain or inflammation in the treated area. An individual is capable of transmitting HPV both during and after treatment, so waiting for wart clearance will not prevent virus transmission. Patients should not have intercourse after surgical treatment until cleared by a health care provider.
How can one Prevent Genital Warts?
Because the warts are caused by a sexually transmitted virus, avoiding sexual contact with new partners can prevent them. However, this may not be realistic for many people. Covering the lesions prior to skin-to-skin contact may block transmission, and thus condom use is advisable for men. However, it is more difficult to block contact with vulvar or labial lesions, or to block oral-genital spread A female condom may be placed within the vagina and over part of the woman’s vulva, and a dental dam (a piece of latex placed over an individual’s mouth and tongue) may be used to avoid oral-genital transmission. These methods have not been formally studied as a means to block HPV transmission.
Currently, a vaccine (Gardasil®) is available which causes immunity to the HPV strains that most commonly cause warts (types 6 and 11), as well as to the strains that most commonly cause cervical cancers (types 16 and 18). The vaccine is effective when given prior to first contact with the virus, and thus it should ideally be given prior to any sexual activity. The Centers for Disease Control and Prevention (CDC) recommends vaccine administration in girls 11-12 years old, with catch-up vaccine for 13-26 year-old unvaccinated females. There are currently no official vaccine guidelines for older women, or for boys and men. Importantly, the vaccine will not cure an infection that has already been established.
What are the Implications of Genital Warts in Pregnancy?
There are two major concerns when pregnant women have genital warts: safe treatment for the mother, and potential transmission to the baby.
Genital warts may grow more rapidly during pregnancy, presumably due to impaired immunity in the pregnant state. Pregnant women may desire treatment to avoid discomfort. Additionally, large warts may block the vaginal opening, or lead to skin abrasions and tears during birth. Podophyllin, podophyllotoxin, 5-fluorouracil, and interferon should not be used during pregnancy, as they can potentially affect the fetus. Imiquimod has not been well studied during pregnancy, and is thus often avoided. This leaves either TCA or cryotherapy as first line therapies for pregnant women, and both are considered safe in this situation.
HPV, including types 6 and 11, may transmit to the fetus during birth. Rarely this can cause a condition called respiratory papillomatosis, where HPV causes disease in the baby’s respiratory tract. This is estimated to occur in 7 out of 1000 women with genital warts. Because medical treatment does not eliminate the virus, it is not recommended solely as a means of preventing transmission. Furthermore, transmission has been documented after delivery by Cesarean section. Due to this finding, the rarity of transmission, and the implications of surgery for the mother, Cesarean section is not recommended for the purpose of preventing transmission.
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