Herpes HSV-1: hitting above the belt
A long-lasting infection with symptoms that come and go, herpes is caused by two types of highly contagious herpes simplex viruses (HSV).
HSV-1 is responsible for cold sores and is also known as recurrent herpes labialis while HSV-2, leads to the sexually transmitted disease referred to as genital herpes.
Although troublesome due to frequent recurrences over the years, herpes infections are usually benign conditions though they can be severe and pose potentially life-threatening complications in predisposed individuals.
As the two diseases have distinctive characteristics, they will be addressed in two separate articles. This one deals exclusively with HSV-1.
HSV-1 infection is found in more than 90 per cent of the population in any given country. The vast majority of infected individuals have no symptoms or signs of the illness and unknowingly transmit the virus to receptive, non-infected people. As the virus is present in the saliva, contamination often occurs in childhood through close contact especially kissing but also by sharing tableware or towels.
Patent HSV-1 infection is observed in about 10 per cent of individuals and affects mainly children below the age of five. The initial symptoms of the first contamination include a burning and itching sensation around the lips or the mouth that lasts for a day or two and is followed by the eruption of small, painful fluid-filled sores or blisters. These blisters burst a few days later leaving open sores that release a virus-infected fluid. A crust then covers the shallow wound, which progressively disappears, usually without scarring. Other symptoms of the first HSV-1 episode include sore throat, minor fever, headache, swollen lymph nodes in the neck and difficulties swallowing due to the blisters. In most cases, complete spontaneous healing takes place within two weeks. The risk of contamination is highest during the outbreak.
Although HSV-1 typically affects the upper part of the body and HSV-2 is mainly present below the belt, oral sex can spread HSV-1 to the genitals and HSV-2 to the lips.
One of the notable features of the herpes simplex virus is its ability to remain dormant or hidden in the nerve cells, likely for a lifetime. The virus can suddenly become active again leading to recurrences that are triggered by various conditions such as minor feverish infection, excessive fatigue or stress, exposure to sunny or cold weather and for females, menstruation.
Recurrences vary in intensity and frequency depending on these factors and on individual susceptibility but are generally milder than the primary infection. As the person get older, recurrences progressively lessen, with fewer, milder and shorter episodes.
Complications may arise especially among high-risk individuals with suppressed immunity due to chemotherapy or HIV infection and can lead to critical brain infection (encephalitis). Children who have eczema (a chronic inflammatory skin rash) may suffer from extensive cold sore infections that require emergency treatment. The virus can also spread to the eyes due to inadvertent scratching, leading to serious ocular disease.
The diagnosis of cold sores is easy and can be made through a simple clinical exam especially when recurrences have occurred. In case of complications, laboratory analyses of the secretions found in the cold sores and blood tests are needed to identify the virus and assess its sensitivity to medicines.
Treatment relies on antiviral medication from the acyclovir group. The medicine is effective in alleviating the symptoms and can be given as a cream to apply on minor lesions and/or tablets for more important manifestations. In cases of severe infection, intravenous administration is required. However, as the drug only reaches the virus within the nerve cells, it does not eradicate the virus from the body and as a result, cannot usually prevent future eruptions.
Prevention focuses on avoiding contact with people who present any suspicious blisters. If you suffer from an outbreak, you should avoid spreading the virus to other parts of your body, especially the eyes and genitals. At-risk individuals may be given prolonged treatment to minimise the frequency of recurrences.
This is the first article in a two-part series on herpes. The second will appear on March 24.
DR GERARD LALANDE is managing director of CEO-Health, which provides medical referrals for expatriates and customised executive medical check-ups in Thailand. He can be contacted at [email protected].
