What are herpes?

Causes and Symptoms

Eight different herpesviruses cause infection in humans. Herpes simplex types 1 and 2 (HHV1 and HHV2) cause cold sores
and genital herpes, while herpes zoster, or varicella-zoster virus, (HHV3) causes chickenpox
(varicella) and shingles. HHV4, also known as Epstein-Barr virus, causes infectious mononucleosis. A variant of this virus has also been implicated in a rare type of lymphoma.
Cytomegalovirus
(HHV5) causes a wide variety of health problems, including serious illness in newborn babies, an illness that strongly resembles infectious mononucleosis, and, in persons with AIDS and other immune deficiencies, disease of the retina, stomach, bowels, liver, lungs, and nervous system. Roseola, one of the many rash-and-fever diseases of childhood, is caused by HHV6. HHV7 is associated with seizures and encephalitis, while HHV8 is associated with Kaposi’s sarcoma
and some lymphomas.

Most commonly, however, the term “herpes” refers to infection with HHV1 and HHV2. A characteristic of both HHV1 and HHV2 infection is blisters clustered on reddened skin or mucous membranes. These blisters then either dry up or break, forming a shallow ulcer, and then crust over and gradually resolve. Another important characteristic is the tendency of infections to recur. This happens because the virus never truly goes away. Rather, it settles in ganglia under the skin and remains latent until some trigger causes it to become active again, resulting in a less severe outbreak at the same site of the body as the primary (first) infection. The trigger may be something physical such as sunburn or a fever, a change in the immune system as with aging, or psychological stress. Recurrences tend to be heralded by itching, tingling, or burning at the site of the original outbreak for hours or days before the blisters occur. Recurrences may be rare or frequent.

Some people are infected with the virus but never have any symptoms. On the other hand, the first infection may cause a person to become very ill. The oral form, called herpetic gingivostomatitis, usually occurs in childhood. Symptoms include painful sores in the mouth, swollen and bleeding gums, swollen glands, and fever. The sores in the mouth may be so severe that it is difficult to eat or drink, and dehydration may become a problem. The genital form of herpes causes painful blisters in the genital area, swollen glands in the groin, fever, and other flulike symptoms. The blisters may make urination extremely painful. Regardless of the site, the first infection usually lasts about two weeks. The blisters themselves may last longer, but they typically scab over without leaving a scar.

Recurrent infections tend to be milder, with a single or small cluster of blisters erupting very close to the original site of infection. Recurrences typically last a shorter time than did the primary infection.

The diagnosis of herpes infection is usually made by observing the characteristic rash. During the first three days of an outbreak, it is possible to culture the virus from the base of one of the ulcers. Blood tests in a person with no current symptoms are not helpful because they do not distinguish between recent infection and one that occurred years before.

Treatment and Therapy

The best treatment for herpes infections is prevention. HHV1 is spread in air droplets, so covering coughs and sneezes is essential. Direct contact with the fluid from the blisters or ulcers can also pass HHV1 or HHV2 from one person to another. Once the blisters have dried up or crusted over, they are much less contagious. Some people with herpes shed low levels of the virus even when they have no blisters. They may not even know they have the infection.

No treatment eliminates the virus from the body, but antiviral drugs will help shorten the length and severity of an outbreak. Continuous antiviral treatment will suppress the virus and prevent recurrences in most cases. Effective antiviral medications are available by prescription. Of these, oral medications are generally more effective than ointments applied directly to the blister. The common antiviral drugs include acyclovir, famciclovir, valaciclovir, and penciclovir. Over-the-counter lysine supplements seem to be helpful for some people, although scientific studies have not proven their effectiveness.

Perspective and Prospects

A wide variety of vaccines, antibodies, and drugs that stimulate the immune system have been tested in the treatment of herpes, but they have either been ineffective or have caused unacceptable side effects. Researchers in the early twenty-first century, however, have found a new type of drug that works to suppress enzymes produced by the virus that seems to be effective in animal models.

Bibliography

American Medical Association. American Medical Association Family Medical Guide. 4th rev. ed. Hoboken, N.J.: John Wiley & Sons, 2004.

Cozic, Charles P. Herpes. San Diego, Calif.: ReferencePoint Press, 2011.

Herpes Resource Center. http://www.herpesresourcecenter.com.

Komaroff, Anthony, ed. Harvard Medical School Family Health Guide. New York: Free Press, 2005.

Parker, James N., and Philip M. Parker, eds. The Official Patient’s Sourcebook on Genital Herpes. San Diego, Calif.: Icon Health, 2002.

Stoppard, Miriam. Family Health Guide. London: Dorling Kindersley, 2006.

Sutton, Amy L. Sexually Transmitted Diseases Sourcebook. Detroit, Mich.: Omnigraphics, 2013.