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Herpes
An outbreak of herpes involves painful sores or ulcers which affect the mouth or genitals. Herpes is caused by a common virus called herpes simplex virus (HSV).
Once you are infected, the virus stays in skin and nerve cells for life. However, you may not know that you are infected with HSV. Most of the time it is dormant and causes no symptoms. From time to time flare-ups do occur, especially if you have a weakened immune system. Even among people without HIV, stress, a common cold or exposure to strong ultra-violet light can cause an outbreak of active herpes.
Oral and genital herpes
There are two main types of HSV which both cause oral and genital infection. HSV-1 usually causes oral herpes or cold sores – tingling or painful spots on the edge of the lip where it meets the skin of the face. These can occasionally develop on the nostrils, on the gums or on the roof of the mouth.
HSV-2 is usually the cause of genital herpes - painful genital or anal ulcers, sometimes accompanied with fever, headache, muscle ache and malaise. Herpes lesions often start as numbness, tingling or itching. This feeling indicates that the virus is travelling up a nerve to the skin. There it causes small bumps that rapidly develop into small inflamed fluid-filled blisters. These burst and crust over, typically taking one of week to heal in people with normal immune systems.
Transmission
The virus can be passed from person-to-person by contact between these lesions and mucous membranes e.g. kissing, sexual contact.
Herpes may also be transmitted when sores are not present, if HSV is replicating and infectious HSV particles are being shed from the skin or, more likely, from mucous membranes. HIV-positive people may experience such shedding more frequently.
Herpes and HIV infection
There is evidence that recent infection with genital herpes ulcers substantially increases the chances of a person being infected with HIV.
In people with HIV, herpes recurrences tend to be more frequent, more severe and longer lasting. Sometimes the lesions can become infected with other bacteria or fungi. As well as causing large oral and genital lesions, herpes can occasionally affect the throat, colon and other organs including the liver, eye and lung. Herpes encephalitis is inflammation of the brain, causing headache, nausea, mental changes, loss of co-ordination and seizures; this is rare in people with HIV but potentially fatal if it does occur.
An HIV-positive person who has herpes ulcers which last for four weeks or longer is diagnosed as having AIDS. There is some evidence that herpes viruses can act as a co-factor in AIDS, activating HIV and making it easier for HIV to infect certain cells.
Diagnosis
HSV is diagnosed by growing (culturing) the virus from a swab taken from a lesion, or by using a fluorescent screening test to detect the virus. A test that looks directly for the virus’ genetic material used for research purposes but is not generally available. Herpes in the oesophagus (gullet) or colon may be examined using fibre-optic instruments.
Treatment and prevention
Herpes infections are treated with acyclovir which is also known by its tradename 'Zovirax'. Other treatments for herpes include valaciclovir, known by the brand name 'Valtrex', and famciclovir.
Acyclovir is taken in tablet form (200-800 mg fives times a day for 5 - 10 days) to treat serious attacks of oral herpes and genital or anal ulcers. Although effective at preventing outbreaks of herpes, once an attack of genital herpes is established acyclovir often provides minimal benefit. It is also given as an intravenous drip (5 - 10 mg/kg every 8 hours) for very severe attacks. Acyclovir has very few side-effects. Acyclovir cannot eliminate HSV virus in nerve cells, so herpes attacks may recur after an attack has been treated. Acyclovir cream is available from chemists to treat cold sores; however, many doctors question its efficacy.
Acyclovir may be taken on a regular basis to prevent recurrent attacks of herpes (400mg twice daily). Frequent use of acyclovir, for treatment or prevention, can lead to drug resistance. Resistance occurs when the virus is no longer sensitive to the treatment. Drug resistance is uncommon except among people with very damaged immune systems. If you have been taking long-term maintenance therapy it is unwise to stop it abruptly, as this may result in a serious herpes outbreak. Placebo-controlled trials have proven that outbreaks of oral herpes can be prevented by moisturisers (e.g. lipsyl) than contain protection against ultra-violet light.
Alternative approaches
Some people believe that diet plays an important part in triggering or suppressing attacks of herpes, although there is no conclusive evidence to support these assertions. There is some research which suggests that an amino-acid called lysine (found in dairy products, yeast and potatoes) may help prevent herpes .
Salt baths are good for relieving the pain of genital herpes lesions.