Herpes simplex—’cold sores’—is a common, blistering condition caused by the Herpes Hominis virus. There are two distinct strains of this virus. Type I is responsible for the more common lip or eye disease, while type II is responsible for the genital disease.
The initial type I infection occurs mainly in infancy and childhood, when it is usually minimal and often unnoticed. The incubation period is between four to five days and is followed by raised antibody levels in the blood and other body fluids such as saliva. These antibodies, however* do not prevent recurrences. Recurrences vary in frequency from weeks to months to years, and appear to be due to reactivation of the virus rather than reinfection. This is thought to be perhaps due to chronic infection of the salivary or tear glands. Alternatively, the virus may persist in the nerve cells of the peripheral nerves, supplying the infected area. Although most type I infections are on the lips, no part of the skin is immune to infection. Fingers, shoulders, buttocks and legs are frequently affected. Commonly, itching or burning precedes the small, grouped blisters by an hour or two. These blisters then rupture and ulcerate, and occasionally become secondarily infected. They normally heal in seven to ten days, sometimes with scarring.
Type II infections occur on and around the genitals of both sexes. They are the commonest cause of genital ulceration seen in the V.D. clinics of Australia, England and the United States. The virus is spread by sexual intercourse, and can cause very painful and long lasting blisters and ulceration. Infections have been on the increase in recent years in most western countries. This is thought to be because of increased sexual activity, young people’s increased mobility, and the replacement of condoms and sheaths by the oral contraceptive pill. There is also some evidence that cancer of the cervix may be more common amongst women who have been infected with the herpes type II virus. Other complications are infection of the newborn, if an infant is born to a mother suffering from active genital herpes. To avoid this, caesarean section is performed in these cases.
The complications of type I infections are quite different and may also be very serious. Corneal (eye) ulcers may occur, and the infection may occasionally become generalized over the entire body, or may affect internal organs, including the liver, heart or brain. This is rare, but can be fatal. Infants or children with atopic eczema should not, for this reason, be nursed or kissed by people with active herpes infection. Similarly, patients with atopic eczema should not be vaccinated with smallpox I variola) vaccine, for fear of developing a generalized eruption.
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