Herpes Simplex Virus Infections

views updated

Herpes Simplex Virus Infections

What Is Herpes Simplex Virus?

How Common Is Herpes Simplex Virus?

How Is Herpes Simplex Virus Spread?

What Happens When Someone Has Herpes Simplex Virus?

Can Infection with Herpes Simplex Virus Be Prevented?


Herpes simplex (HER-peez SIM-plex) virus is a virus that can cause several types of infections, including sores on the skin, usually around the mouth or in the genital* area.

(JEH-nih-tul) refers to the external sexual organs.


for searching the Internet and other reference sources

Cold sores

Fever blisters

Genital herpes

Herpes gladiatorum

Herpes keratitis

Herpes labialis

Herpes simplex

Herpesvirus family

Herpetic whitlow



Oral herpes

What Is Herpes Simplex Virus?

There are two types of the herpes simplex virus (HSV): HSV-1 and HSV-2. Both are part of the herpesvirus (her-peez-VY-rus) family, a group of viruses with similar traits that also includes the varicella zoster (var-uh-SEH-luh ZOS-ter) virus, which causes chicken pox, and the Epstein-Barr (EP-steen BAR) virus, which causes infectious mononucleosis.

HSV-1 causes small, clear blisters (also known as cold sores, fever blisters, or oral herpes) on the skin. Cold sores usually occur on the face, particularly around the mouth and nose, but they can pop up anywhere on the skin or mucous membranes*. They may show up one at a time or in groups. The painful blisters can break, bleed, and crust over, leaving red spots of healing skin. When the sores appear, this is known as a herpes outbreak.

*mucous membranes
are the moist linings of the mouth, nose, eyes, and throat.

High-school and college wrestlers sometimes develop herpes blisters on their shoulders and back from close contact with one another and from virus-contaminated mats, a condition called herpes gladiatorum. Rugby players also commonly pass along HSV-1 through close physical contact during matches, with the blisters nicknamed scrum pox. Small HSV-1 sores known as herpetic whitlow can appear on the fingers, especially in children who bite their nails or suck their fingers, which spreads the virus from the mouth to the hands. HSV-1 infection can occur in other situations as well when the virus comes in contact with broken skin.

Although the HSV-1 virus occasionally causes blisters in the genital area, it is usually HSV-2, also known as genital herpes, that causes sores on the penis in sexually active males and on the vulva*, vagina, and cervix* in sexually active females. Both sexes can develop herpes blisters around the anus and on the buttocks. HSV-2 occasionally produces sores on other parts of the body, such as the mouth or throat. Having genital herpes also increases a persons risk of getting HIV (the virus that causes AIDS*) if he or she has unprotected sex with a person who is HIV-positive.

(VUL-vuh) refers to the organs of the female genitals that are located on the outside of the body.
(SIR-viks) is the lower, narrow end of the uterus that opens into the vagina.
or acquired immunodeficiency (ih-myoo-no-dih-FIH-shensee) syndrome, is an infection that severely weakens the immune system; it is caused by the human immunodeficiency virus (HIV).

Herpes simplex virus type 1 causes small, clear blisters to appear around the mouth and nose. Also called cold sores, fever blisters, or sun blisters, they typically unite to form a larger sore. Custom Medical Stock Photo, Inc.

When the herpes simplex virus enters the body for the first time, this is called a primary infection. Once primary infection occurs, HSV-1 and HSV-2 remain in the body for life. The virus travels to the bodys nerve cells and lies dormant (inactive) until it reactivates, as during a herpes outbreak. Emotional or physical stresses (like exhaustion or an illness), sun exposure, menstruation, or fever can all trigger such an outbreak, but sometimes active herpes infection returns for no apparent reason. These outbreaks are known as recurrent infections. Recurrent infections often appear close to or at the area where the primary infection occurred. For example, repeated outbreaks of HSV-1 may cause cold sores in the same spot along the outer border of the lips, but they also can occur anywhere around the mouth.

How Common Is Herpes Simplex Virus?

Both HSV-1 and HSV-2 are common. Between 50 and 80 percent of adults in the United States are infected with oral herpes by age 30. It is estimated that every year up to 1 million people in the United States become infected with genital herpes, and the disease is on the rise among sexually active adults. According to the U.S. Centers for Disease Control and Prevention, at least 45 million people, or about one in five adolescents and adults, in the United States now have genital herpes.

How Is Herpes Simplex Virus Spread?

Both types of herpes simplex virus are contagious, which means they can be passed from person to person. Both types can spread when someone comes into direct contact with an infected persons skin or saliva. Many people with oral herpes first became infected when they were children, perhaps from contact with a family member. Kissing or sharing dishes or eating utensils with someone who has oral herpes can lead to HSV-1 infection.

If a person has unprotected vaginal, oral, or anal sex with someone infected with HSV-2 (whether or not sores are present on the skin at the time of sexual contact), that person is at risk for contracting genital herpes. HSV-2 does not spread from toilet seats or hot tubs.

People with either HSV-1 or HSV-2 can pass the virus to others even when they do not have an active herpes outbreak. Research suggests that at least 60 percent of new cases of herpes simplex are acquired when the person transmitting the infection has no noticeable blisters or sores.

What Happens When Someone Has Herpes Simplex Virus?

Signs and symptoms

Symptoms of an active HSV-1, or oral herpes, infection may include:

  • tenderness, tingling, or itching in the spot where the blister eventually appears
  • blisters or sores (which are often painful) on the lips, face, neck, and shoulders
  • fever or symptoms like those of the flu

Symptoms of an active HSV-2, or genital herpes, infection may include:

  • fever or symptoms like those of the flu
  • reddish rash
  • itching or tingling of the genitals
  • swollen glands (lymph nodes)
  • burning feeling during urination
  • muscle aches
  • discharge from the vagina or penis
  • blisters or sores (which are often painful)

Dont Confuse Canker Sores and Cold Sores

What is the difference between cold sores and canker sores? Canker sores are small, red sores inside the mouth that turn white. Unlike cold sores, canker sores are not caused by the herpes simplex virus. Doctors and scientists think that stress may cause canker sores, but they are not sure. Both canker sores and cold sores are painful, but canker sores only appear inside the mouth, not on the face, lips, or neck, where cold sores occur.


Doctors can often diagnose outbreaks of HSV-1 or HSV-2 based upon the appearance and location of the sores. Sometimes, however, sores in the genital region may be difficult to recognize, as they can resemble those of other sexually transmitted infections.

Tests to positively diagnose herpes simplex infection involve scraping the blister and culturing* the sample to see if the herpes virus grows. Sometimes, doctors use a Tzanck preparation, a scraping of a blister examined under a microscope to look for signs of the virus, to help quickly confirm a diagnosis. A doctor may also take a sample of a persons blood to look for antibodies* to the herpes virus or to test for evidence of herpes DNA* in the blood.

(KUL-chur-ing) means subjecting to a test in which a sample of fluid or tissue from the body is placed in a dish containing material that supports the growth of certain organisms. Typically, within days the organisms will grow and can be identified.
(AN-tih-bah-deez) are protein molecules produced by the bodys immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.
or deoxyribonucleic acid (dee-OX-see-ry-bo-nyoo-klay-ik AH-sid), is the specialized chemical substance that contains the genetic code necessary to build and maintain the structures and functions of living organisms.


There is no cure for either type of the herpes simplex virus. Currently, antiviral medications can help control outbreaks of herpes virus and are used to treat genital herpes or sometimes recurrent cold sores from HSV-1. Some over-the-counter ointments or creams may help reduce the pain of cold sores, but they do not necessarily speed healing or prevent the sores from returning. For painful herpes simplex outbreaks, applying ice to the area, drinking cold drinks, or taking over-the-counter pain medication such as acetaminophen (uh-see-teh-MIH-nohfen) can ease discomfort. People with active cold sores may also want to avoid acidic foods such as tomatoes, lemons, and oranges because these can irritate open sores on the lips or in the mouth.

Both HSV-1 and HSV-2 remain in the body for life and can cause future outbreaks, the severity of which varies greatly from person to person. When someone develops a primary infection, the symptoms may last from 2 to 4 weeks. The course of recurrent herpes infections is usually shorter than the primary one.

On average, people with genital herpes experience 4 to 5 outbreaks of herpes each year. Although the virus will always be in the body, over time the number of outbreaks usually decreases.


People with either type of herpes simplex infection may experience pain, embarrassment, or emotional stress when they have an outbreak, although the infections usually are not dangerous.

In rare cases, however, (usually in people with weakened immune systems) herpes can infect the skin surrounding the eye. The virus then can enter the eyes cornea*, causing a condition called herpes keratitis. This may lead to scarring of the eye and blindness if left untreated.

(KOR-nee-uh) is the transparent circular layer of cells over the central colored part of the eyeball (the iris) through which light enters the eye.

Infants born to women with genital herpes are at risk for serious complications from HSV-2 infection as they pass through the birth canal during delivery, particularly if the woman has an outbreak of sores. People who have immune systems weakened by disease, such as people with cancer or AIDS, or those with an organ transplant can also become very ill and may die from herpes simplex infection. The virus can spread throughout the body, causing life-threatening infections in the lungs, liver*, and other organs. In some cases, herpes simplex may also infect the brain, causing a dangerous inflammation known as viral encephalitis (en-seh-fuh-LYE-tis).

is a large organ located beneath the ribs on the right side of the body. The liver performs numerous digestive and chemical functions essential for health.

Can Infection with Herpes Simplex Virus Be Prevented?

There is no vaccine* against either HSV-1 or HSV-2, but researchers are working to develop one. Because so many people have oral herpes and because HSV-1 can be spread even when people do not have visible blisters, it is difficult to prevent. To reduce the risk of getting oral herpes, experts recommend not kissing someone with active cold sores and not sharing lipstick, towels, razors, silverware, food, glasses, or utensils with anyone, especially someone who has had cold sores or currently has them.

(vak-SEEN) is a preparation of killed or weakened germs, or a part of a germ or product it produces, given to prevent or lessen the severity of the disease that can result if a person is exposed to the germ itself. Use of vaccines for this purpose is called immunization.

Using sunscreen when outside, especially on areas prone to blisters, may reduce the likelihood of an outbreak of cold sores in anyone infected with HSV-1. Experts advise that people with active cold sores around the mouth always wash their hands before touching the genitals or buttocks.

Ways of reducing the risk of getting genital herpes include practicing abstinence (not having sex) or by always using a latex condom, because someone with genital herpes is contagious even if no blisters are visible. A condom does not protect all of the skin in the genital region, so anyone with known genital herpes should not have sex during outbreaks of blisters.

See also

AIDS and HIV Infection


Mononucleosis, Infectious

Sexually Transmitted Diseases

Varicella (Chicken Pox) and Herpes Zoster (Shingles)



American Social Health Association (ASHA), P.O. Box 13827, Research Triangle Park, NC 27709. The ASHA provides information about herpes symptoms and prevention methods in its National Herpes Resource Center. The ASHA also operates the National Herpes Hotline, to provide referrals and information to anyone with questions about herpes.

Telephone 919-361-8488 http://www.ashastd.org

U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC is the U.S. government authority for information about infectious and other diseases. The CDCs division of STD prevention offers information about genital herpes and how to prevent it and other sexually transmitted diseases, as well as a hotline to call for questions about herpes and other STDs.

Telephone 800-227-8922 http://www.cdc.gov/std


KidsHealth.org. KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of childrens health. It contains articles on a variety of health topics, including herpes.


About this article

Herpes Simplex Virus Infections

Updated About encyclopedia.com content Print Article