Human Papillomavirus and Genital Warts
What is human papillomavirus?
Human papillomavirus (HPV) is one of the most common causes of
sexually transmitted infection (STD) in the world. Health experts
estimate that there are more cases of genital HPV infection than of
any other STD in the United States. According to the American Social
Health Association, approximately 5.5 million new cases of sexually
transmitted HPV infections are reported every year. At least 20
million Americans are already infected.
Scientists have identified more than 100 types of HPV, most of
which are harmless. About 30 types are spread through sexual contact.
Some types of HPV that cause genital infections can also cause
cervical cancer and other genital cancers.
Like many STDs, genital HPV infections often do not have visible
signs and symptoms. One study sponsored by the National Institute of
Allergy and Infectious Diseases (NIAID) reported that almost half of
the women infected with HPV had no obvious symptoms. People who are
infected but who have no symptoms may not know they can transmit HPV
to others or that they can develop complications from the virus.
What are genital warts?
Genital warts (condylomata acuminata or venereal warts) are the
most easily recognized sign of genital HPV infection. Many people,
however, have a genital HPV infection without genital warts.
Can HPV cause other kinds of warts?
Some types of HPV cause common skin warts, such as those found on
the hands and soles of the feet. These types of HPV do not cause
How are genital warts spread?
Genital warts are very contagious and are spread during oral,
genital, or anal sex with an infected partner. About two-thirds of
people who have sexual contact with a partner with genital warts will
develop warts, usually within three months of contact.
In women, the warts occur on the outside and inside of the vagina,
on the opening (cervix) to the womb (uterus), or around the anus. In
men, genital warts are less common. If present, they usually are seen
on the tip of the penis. They also may be found on the shaft of the
penis, on the scrotum, or around the anus. Rarely, genital warts also
can develop in the mouth or throat of a person who has had oral sex
with an infected person.
Genital warts often occur in clusters and can be very tiny or can
spread into large masses in the genital or anal area.
How are genital warts diagnosed?
A doctor or other health care worker usually can diagnose genital
warts by seeing them on a patient. Women with genital warts also
should be examined for possible HPV infection of the cervix.
The doctor may be able to identify some otherwise invisible warts
in the genital tissue by applying vinegar (acetic acid) to areas of
suspected infection. This solution causes infected areas to whiten,
which makes them more visible, particularly if a procedure called
colposcopy is performed. During colposcopy, the doctor uses a
magnifying instrument to look at the vagina and cervix. In some
cases, the doctor takes a small piece of tissue from the cervix and
examines it under the microscope.
A Pap smear test also may indicate the possible presence of
cervical HPV infection. In a Pap smear, a laboratory worker examines
cells scraped from the cervix under a microscope to see if they are
cancerous. If a woman's Pap smear is abnormal, she might have an HPV
infection. If a woman has an abnormal Pap smear, she should have her
doctor examine her further to look for and treat any cervical
What is the treatment for genital warts?
Genital warts often disappear even without treatment. In other
cases, they eventually may develop a fleshy, small raised growth that
looks like cauliflower. There is no way to predict whether the warts
will grow or disappear. Therefore, if you suspect you have genital
warts, you should be examined and treated, if necessary.
Depending on factors such as the size and location of the genital
warts, a doctor will offer you one of several ways to treat them.
- Imiquimod, an immune response cream which you can apply to the
- A 20 percent podophyllin anti-mitotic solution, which you can
apply to the affected area and later wash off
- A 0.5 percent podofilox solution, applied to the affected area
but shouldn't be washed off
- A 5 percent 5-fluorouracil cream
- Trichloroacetic acid (TCA)
If you are pregnant, you should not use podophyllin or podofilox
because they are absorbed by the skin and may cause birth defects in
your baby. In addition, you should not use 5-fluorouracil cream if
you are expecting.
If you have small warts, the doctor can remove them by freezing
(cryosurgery), burning (electrocautery), or laser treatment.
Occasionally, the doctor will have to use surgery to remove large
warts that have not responded to other treatment.
Some doctors use the antiviral drug alpha interferon, which they
inject directly into the warts, to treat warts that have returned
after removal by traditional means. The drug is expensive, however,
and does not reduce the rate that the genital warts return.
Although treatments can get rid of the warts, none gets rid of the
virus. Because the virus is still present in your body, warts often
come back after treatment.
Can HPV and genital warts cause complications?
Some types of HPV can cause cervical cancer. Others, however,
cause cervical cancer and also are associated with vulvar cancer,
anal cancer, and cancer of the penis (a rare cancer).
Most HPV infections do not progress to cervical cancer. If a woman
does have abnormal cervical cells, a Pap test will detect them. It is
particularly important for women who have abnormal cervical cells to
have regular pelvic exams and Pap tests so that they can be treated
early, if necessary.
Pregnancy and Childbirth
Genital warts may cause a number of problems during pregnancy.
Sometimes they get larger during pregnancy, making it difficult to
urinate. If the warts are in the vagina, they can make the vagina
less elastic and cause obstruction during delivery.
Rarely, infants born to women with genital warts develop warts in
their throats (laryngeal papillomatosis). Although uncommon, it is a
potentially life-threatening condition for the child, requiring
frequent laser surgery to prevent obstruction of the breathing
passages. Research on the use of interferon therapy in combination
with laser surgery indicates that this drug may show promise in
slowing the course of the disease.
Note: All information is based upon materials published by the National
Institute of Allergy and Infectious Diseases (NIAD) and the
U.S. Centers for Disease Control.