Genital warts are a common sexually transmitted infection (STI) caused by certain strains of the human papillomavirus (HPV). There are over 100 different strains of HPV, with around 40 strains that specifically affect the genitals. Genital warts present as soft, skin-colored growths that appear on the genitals and sometimes the mouth and throat. While most strains of genital HPV do not cause any symptoms, some can lead to genital warts or cancer. Understanding which STDs can cause genital warts is important for getting proper treatment and preventing further transmission.
HPV
Human papillomavirus (HPV) is by far the most common STD that causes genital warts. There are over 150 known strains of the HPV virus, with around 40 strains that specifically infect the genitals. The strains that cause genital warts are considered “low risk” and do not cause cancer. The “high risk” cancer-causing strains include HPV 16 and 18, which are responsible for around 70% of cervical cancers. Both low and high risk HPV strains are extremely common – the CDC estimates that around 79 million Americans are currently infected with HPV, with about 14 million new cases every year.
The strains of HPV that most commonly cause genital warts include:
- HPV 6
- HPV 11
- HPV 42
- HPV 43
- HPV 44
These strains of HPV only cause external genital warts – they do not lead to cancer. However, having genital warts increases the risk of acquiring a high risk cancer-causing HPV strain through sexual activity. HPV is primarily spread through vaginal, oral, and anal sex without a condom. Using condoms reduces, but does not completely prevent, HPV transmission.
How HPV Causes Warts
HPV infects the epithelial cells of the skin and mucous membranes. The virus causes these infected cells to grow and multiply excessively, resulting in benign outgrowths known as warts. The strains of HPV that cause genital warts preferentially infect the moist tissues of the genitals, anus, mouth and throat. In some cases, the virus can lay dormant for years before activating and causing warts to appear. People infected with HPV may never develop visible warts.
Genital warts start out as small, flesh-colored or white bumps that grow into larger clusters. They have a cauliflower-like surface and do not cause any pain or discomfort. However, they can be unsightly, itchy, or prone to bleeding during intercourse. Warts may appear within weeks or months after infection with HPV. But in some cases they emerge years later when the immune system is weakened.
Other STDs that Can Cause Genital Warts
While HPV is by far the most common cause of genital warts, a couple other STDs can sometimes cause similar wart-like growths in the genital region:
- Molluscum Contagiosum: This common viral infection causes small, painless bumps that resemble warts. However, molluscum warts tend to have an indentated center and pearly white color. They can appear on the genitals and other parts of the body. Molluscum is spread through both sexual and non-sexual skin to skin contact.
- Genital Herpes: HSV-1 or HSV-2 infections can sometimes produce wart-like sores in the genital region. However, herpes lesions are typically smaller with a blister-like appearance. They also cause tingling, pain, and itching.
Getting Tested for HPV
Since genital warts are caused by HPV infection, diagnostic tests focus on detecting the virus itself. Some key HPV tests include:
- HPV DNA Test: This test detects the genetic material (DNA) of high risk HPV strains, including the types that can cause genital warts. It involves swabbing cells from the cervix or anogenital region and analyzing them at a laboratory.
- HPV mRNA Test: This looks for messenger RNA created by HPV infection in cervical/genital cells. It can identify active HPV infections.
- HPV Genotyping Test: This determines the exact strain of HPV present. It can identify whether someone is infected with a wart-causing low risk strain versus a high risk cancer-causing strain.
- Pap Smear: Pap smears do not test specifically for HPV, but can reveal abnormal cervical cells caused by an active HPV infection.
A visual exam of the genitals may be done to inspect for external warts. However, warts do not always appear even with an active low risk HPV infection. Getting tested through HPV DNA, mRNA, or genotyping can help identify infection even without visible warts.
Treatment for Genital Warts
Several treatments options exist for removing external genital warts caused by HPV:
- Topical Medications: Prescription topical creams containing imiquimod, podofilox, sinecatechins, etc can help clear warts.
- Cryotherapy: Freezing warts with liquid nitrogen destroys abnormal tissue.
- Surgical Removal: Cutting away warts by electrocautery, laser ablation, excision, etc.
- Trichloroacetic Acid: Chemical solution dissolves away genital wart tissue.
Removing visible genital warts does not cure the underlying HPV infection. Warts often recur after treatment because latent HPV remains in the body. Even after warts are gone, it is still possible to transmit HPV to sexual partners.
Preventing HPV Transmission
HPV is extremely common – the CDC estimates nearly all sexually active adults get infected at some point. Using condoms during sex offers some protection against HPV, but does not completely prevent transmission or warts. The most effective prevention is vaccination:
- The Gardasil vaccine protects against the wart-causing strains HPV 6 and 11, in addition high risk cancer-causing strains 16 and 18.
- The Gardasil-9 vaccine protects against strains 6, 11, 16, 18, plus five other cancer-causing strains (31, 33, 45, 52, 58).
The CDC recommends all preteens ages 11-12 receive the HPV vaccine. It is most effective when administered before any exposure through sexual activity. The vaccine is approved for women up to age 45 and men up to age 26. Condoms should still be used to lower transmission risk.
Partners of Individuals with Genital Warts
Sexual partners of someone diagnosed with genital warts may also require testing and treatment. Even if no warts are visible, the partner may harbor the same strain of wart-causing HPV. Testing partners through HPV DNA or genotyping can identify infection even without physical warts. Treating partners helps prevent back-and-forth transmission within a relationship.
Condoms reduce HPV transmission risk somewhat, but do not offer full protection because the virus can be present on surrounding genital skin. Limiting the number of sexual partners is advisable to avoid exposure to different HPV strains.
Partners can consider HPV vaccination to prevent future warts or cervical cancer. However, it will not treat an active infection already present.
Pregnancy and Genital Warts
Pregnant women with genital warts may safely undergo cryotherapy, surgical excision, or topical treatments. However, certain prescription topical medications may not be used. Treating warts reduces the risk of transmission to the baby during vaginal delivery.
HPV can rarely be transmitted from mother to newborn during pregnancy or delivery, potentially causing recurrent respiratory papillomatosis (RRP). This causes wart-like growths in the throat that can block breathing. C-section delivery reduces this risk.
The Gardasil and Gardasil-9 vaccines are not approved for pregnant women. But women who receive the HPV vaccine prior to pregnancy are less likely to have genital warts during pregnancy.
HPV and Cancer Risk
The strains of HPV that cause genital warts are considered low risk because they do not cause cancer. However:
- Having genital warts may indicate sexual behaviors that could increase risk of contracting a cancer-causing high risk HPV strain.
- The presence of warts means the immune system did not clear HPV, suggesting potential susceptibility to other HPV strains.
For these reasons, anyone diagnosed with genital warts should undergo regular cervical, anal, and oral cancer screenings as recommended by their healthcare provider.
Psychological Effects of Genital Warts
For many people, a diagnosis of genital warts causes significant emotional distress:
- Anxiety, depression, anger about the infection.
- Fear of rejection from sexual partners.
- Worry about infertility, cancer.
- Embarrassment, low self-esteem due to warts.
Seeking counseling can help individuals cope psychologically with genital warts. Partners should offer emotional support and remind the infected person it is a common condition. Joining a support group may help reduce stigma.
Conclusion
Genital warts are extremely common benign growths caused by certain strains of HPV. While unsightly and emotionally distressing, they do not cause serious health complications. Visible warts can be removed, but HPV itself cannot be cured. Vaccination, condoms, limiting partners, and screening are key for prevention and risk reduction. With proper treatment and support, most people recover without major issues and avoid spreading HPV further.