Alternative Names herpes genitalis, herpes simplex genial infection, herpes infection of the genitals
Definition Genital herpes is a sexually transmitted disease caused by the herpes simplex virus. The disease causes painful blisters on the genitals.
What is going on in the body? Herpes simplex virus type 2 causes most cases of genital herpes. Type 1 herpes simplex virus causes the other 10% to 25% of cases. Type 1 herpes also causes the mouth ulcers called cold sores, and is carried by most people. The virus infects nerve cells and remains in the body permanently after infection. When a person is first infected, blisters form in what is called the primary episode. The blisters can then recur at any time in the future. The primary episode is usually more severe than the recurrences. Recurrences last about 10 days. The virus is harboured within nerve tissue even when there are no blisters and may be transmitted to others.
What are the signs and symptoms of the infection? Multiple blisters on the genitals may come together into larger blisters. The blisters are usually 1 to 2 millimetres wide, with red edges. The blisters are soft, and usually painful and tender. The lymph nodes or "glands" in the groin can swell painfully as well. There may be other symptoms, especially during the primary episode. These include pain on urination, discharge from the urethra and the retaining of urine. The urethra is the tube that carries urine from the bladder to the outside of the body. The nervous system may become inflamed, causing constipation, weakness, impotence, sensory loss or other symptoms.
What are the causes and risks of the infection? Genital herpes is transmitted by sexual contact. It is most contagious when there are active blisters, but it can still be spread when the infection is quiet. Herpes simplex virus type 1, which causes oral blisters, is much more common than herpes simplex type 2, the usual cause of genital herpes. Depending on the country, herpes simplex virus type 1 is carried by between 30% and 100% of adults. In Australia, herpes simplex virus type 2 is thought to be carried by one of every five adolescents and adults. Most people who have herpes never know it.
What can be done to prevent the infection? Herpes simplex virus infections are spread by close contact with a person who is actively shedding viral particles. The person usually has blisters during shedding, but the skin might look quite normal. Sexual intercourse is not necessary for transmission of genital herpes. Condoms do not offer complete protection since blisters can occur on skin surfaces not covered by the condom.
How is the infection diagnosed? The clinical clues are groups of soft, painful blisters on a red base. Laboratory tests are not usually needed, but are available for unusual cases.
What are the long-term effects of the infection? Genital herpes rarely takes a dangerous course in healthy people. People with severe immune system problems, such as those with AIDS, may have a life-threatening infection due to genital herpes. Genital herpes in pregnant women may be passed to a newborn during passage down the birth canal and can cause serious disease in the child. Once a herpes infection is acquired, it remains in the body for life. Most people have a return of blisters periodically.
What are the risks to others? Genital herpes is a contagious disease. The exact risk of transmission from a single exposure is unknown.
What are the treatments for the infection? Acyclovir, valacyclovir, and famciclovir are the most commonly used drugs for genital herpes. These act by reducing the amount of time that viral particles are shed. These drugs also help the blisters to heal faster. Acyclovir can be taken orally, or injected or used in an ointment, while valacyclovir and famciclovir are available only as a pill. These drugs can also be taken between recurrences to help reduce the frequency of recurrences.
What are the side effects of the treatments? The drugs to treat genital herpes can occasionally cause nausea, vomiting, diarrhoea, headaches, or a rash. More serious side effects, such as kidney or nerve damage, are quite rare at the common doses used.
What happens after treatment for the infection? Medications may reduce but will not stop active blisters and shedding of viral particles. There is no cure for this infection and treatment may be needed for life if symptoms are severe or bothersome.
How is the infection monitored? People can generally monitor the condition on their own at home. Some people familiar with their disease are given medication to use at home for when blisters return.
Author: Stuart Wolf, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
