What is Human Papillomavirus?
Human Papillomavirus (HPV) also known as wart virus or genital warts, is a particular type of virus that affects epithelial surfaces. Epithelium basically refers to a layer of cells. HPV usually causes warts in various parts of the body including the skin of palms (palmar warts), soles (plantar warts) and genitals. In addition, there are some types of HPV that can predispose to cervical cancer.
Statistics on Human Papillomavirus
HPV infection is extremely common and is thought to affect approximately 10-20% of women. Common plantar and palmar warts are the most common presentations of HPV in children and young adults. Genital warts are common amongst sexually active people.
However, not all patients with the virus will have symptoms or evidence of warts. Thus you or your partner may not know you have the virus and can pass it on unknowingly to each other.
Note that HPV is associated with cervical cancer and is found in over 95% of patients with this particular malignancy. Cervical cancer is now one of the leading causes of cancer deaths in Australian women.
Risk Factors for Human Papillomavirus
HPV is usually spread via sexual intercourse (known as a sexually transmitted infection – STI), skin-to-skin contact (especially if there are breaks in the skin) or to a baby during childbirth. There are therefore a number of factors that can increase your risk of disease:
- Multiple sexual partners- Note that condom use can reduce your risk but is not 100% effective as the virus can still be passed via direct skin contact.
- A partner who has had multiple previous sexual partners.
- Tobacco and alcohol use.
- Stress and the presence of other viral infections (such as HIV or herpes) at the same time.
- Problems with the immune system.
Some types of HPV particularly types 16 and 18 are associated with greater risks of cervical cancer. There are also a number of factors that can increase susceptibility such as tobacco use, ultraviolet radiation exposure, pregnancy, folate deficiency, and immune suppression.
Progression of Human Papillomavirus
Common warts can be hard to treat but tend to eventually resolve spontaneously, probably due to the body’s own immune response. Genital wart outbreaks can usually be controlled but are commonly associated with recurrences. Note that even if the virus is treated, you can still affect others.
As fore mentioned, some subtypes of HPV (HPV-16 and HPV-18) can lead to abnormal changes in cells (dysplasia) and increase your risk of squamous cell carcinoma of the cervix. This emphasises the importance of regular pap smears to detect and monitor the disease.
Symptoms of Human Papillomavirus
HPV can present in a number of ways as follows:
- You may notice the appearance of wart-like lesions on the palms, or soles or genitalia.
- You may have increased dampness or moisture in the area of the growths.
- If you have genital warts you may experience cause itching of the penis, scrotum, anal or vulvar areas.
- Women may notice abnormal vaginal bleeding (not associated with a menstrual period) after sexual intercourse.
However, sometimes HPV infection can occur with no symptoms at all, thus it is important that you undergo the appropriate screening for the condition if you are considered at high risk.
When you present to your doctor, they will ask you detailed questions about your symptoms. They will also ask you about your sexual history and number of sexual partners. In addition they will ask about lifestyle factors (such as smoking) that can increase your risk of infection and transformation into cervical cancer.
HPV infection in children usually presents with common warts on the hands or other areas of the body. Anogenital warts are rare in children and their presence may suggest child abuse. Very rarely however, these types of warts can be acquired by non-sexual contact.
Clinical Examination of Human Papillomavirus
Your doctor will carefully examine your skin to determine the features of the warts. If indicated they will also need to perform a full genital and pelvic examination. There are various different manifestations of HPV as follows:
- Common warts – These appear as small rough lesions on the palms or feet. They can have small red or black spots seen within their surface which is due to leakage of blood from small vessels.
- Plantar warts – These tend to be flatter lesions that sometimes can be indrawn into the skin. They are found on the soles of the feet. Sometimes they may turn black and painful before spontaneously disappearing.
- Planar warts – These are a rarer type of wart that are smaller and flatter. They are usually found on the face or backs of the hands.
- Anogenital warts – These are lesions found around the genitals or anus. They are usually in moist areas but occasionally may be seen in dry areas such as the shaft of the penis. The classic appearance of genital warts is described as cauliflower-like lesions.
- Mucosal warts – Very rarely your doctor may find warts in other sites of the body including the nose, mouth, larynx or conjunctiva (membrane lining the surface of the eye). These warts tend to be benign but warts in the larynx in children can be serious as they can lead to obstruction of the airways.
How is Human Papillomavirus Diagnosed?
Your doctor may perform a number of tests to confirm the diagnosis of HPV including:
- Pap Smears – This is the most common screening test for cervical cancer. The special spear can detect specific cellular changes that occur in viral infection. In addition Pap smears can detect early abnormal cellular changes that suggest early cervical cancer.
- Colposcopy – Occasionally your doctor may send you for a more specialised test where the inside lining of the vagina and cervix can be visualised using a microscope. This allows even smaller lesions to be seen. Small biopsies (tissue samples) can also be collected. Sometimes vinegar or acetic acid is applied to the mucosa to highlight the lesions more easily.
- DNA test – Special tests are available that aim to detect the actual virus (rather than characteristic changes) from swabs or tissue samples.
If you have genital warts it is also recommended that you are screened for other sexually transmitted infections. Your doctor may perform vaginal/cervical swabs in women, as well as obtaining a urine sample for chlamydia and gonorrhoea testing, and blood tests for syphilis, hepatitis B and hepatitis C, and occasionally HIV. You will need to give your consent for these investigations to be performed. Your doctor will describe in more details the benefits and implications of these tests.
Human Papillomavirus Prevention
It is probably the best management to try and avoid acquiring HPV. This can be achieved by minimising sexual partners and using safe sex practices such as barrier contraception (condoms). Recently a vaccine called Gardisil has been introduced that specifically protects against HPV infection. This has been shown to reduce up to three quarters of cervical cancers. The vaccine is currently covered by Medicare for females aged 9-26. In older women the vaccine is less effective as they will most likely have already obtained the virus.
Note that there has been some debate over the HPV vaccine saying it is a ‘sex vaccine’ and that abstinence is a better option. However you should recognise that the vaccine is safe and provides protection against a leading cause of death in women. If used correctly it offers major benefits to women. You should however continue to have safe sex practices as it does not protect against other sexually transmitted infections. Furthermore regular pap smears are still required for women who have received the vaccine.
How is Human Papillomavirus Treated?
The main aim of treatment for HPV is to reduce symptoms and in the case of genital infections ensure any dysplasia is eradicated. Most common warts will eventually resolve on their own but this can sometimes take years. If your warts cause pain or discomfort or cause cosmetic problems, you can opt to have them treated. Unfortunately however, recurrences of warts are common. A number of different treatment options are available to treat warts as follows:
- Cryotherapy – This is a common method for treating warts and other skin lesions. Liquid nitrogen is used to freeze the wart, which eventually blisters and falls off. This treatment however can be painful and sting.
- Cautery – This involves using an electrical current to burn off the lesion. Laser therapy is another alternative.
- Chemical treatments – Certain drugs can be applied topically to the lesion which alter the immune response to the HPV virus or kill abnormal cells. Some agents may also be injected.
- Surgery – Occasionally large warts may be removed by cutting them out.
Genital warts should always be treated by a doctor. You should not use over-the-counter remedies meant for other kinds of warts. Your doctor may treat genital warts by applying a skin treatment in the office or the doctor may prescribe a medication that you apply at home several times per week. If you develop genital warts, all of your sexual partners must be examined by a health care provider and treated if genital warts are found. After your initial treatment, your doctor will schedule follow-up examinations to see if the warts have returned.
Women who have had genital warts, and female partners of men with a history of genital warts, should have a pap smear at least every 6 months. For warts on the cervix, women may be advised to have pap smears every 3 months after initial treatment.
For more information on different types of sexually transmitted infections, prevention of STIs, treatments and effects on fertility, see Sexually transmitted infections (STIs).
Human Papillomavirus References
- Gearhart P, Randall T. Human papillomavirus, eMedicine, 2007. Available [online] at URL: http://www.emedicine.com/med/topic1037.htm
- Hines J, Ghim S, Jenson A. Human papillomavirus infection, BMJ 1996; 312: 522-523.
- Kumar P, Clark M. Clinical Medicine, Fifth Ed, W.B. Saunders, 2002.
- Murray P, Rosenthal K, Kobayashi G, Pfaller M. Medical Microbiology, 4th Ed, Mosby, Sydney, 2002.
- Schiffman M, Castle P, When to test women for human papillomavirus, BMJ 2006; 332: 61-62.