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Herpes Simplex

Written by Ada’s Medical Knowledge Team

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What is herpes simplex?

Herpes simplex, typically referred to as “herpes” or HSV, is a viral infection caused by the herpes simplex virus. The virus comes in two varieties: Herpes type one (HSV-1) and herpes type two (HSV-2).

Although it can occasionally cause genital herpes, herpes type one (also called herpes labialis) generally leads to sores around the mouth, whereas herpes type two generally leads to genital sores. These sores, also known as cold sores or fever blisters, can be painful but are generally manageable. As yet, there is no known cure for the herpes simplex virus.[1]

Symptoms of herpes simplex

Many people who contract the herpes simplex virus do not display any signs or symptoms of infection. If an individual does begin to display symptoms they will normally develop within two to 20 days after the initial infection and may include:[2]

  • An itching or burning sensation: This generally precedes the development of sores and can occur around the mouth or genitals.
  • Sores: May occur singularly or in clusters. Sores begin as fluid-filled blisters and will generally ooze and crust over before healing. Typically, they last for between seven and 10 days. Oral herpes will normally cause sores to appear on the face or lips, whereas the penis, vagina, buttocks or anus are the most common locations for genital herpes sores.
  • Flu-like symptoms: Fatigue, muscle pain, fever and swollen glands in the neck or genital area are possible.
  • Urination problems: People with genital herpes (especially women) may experience pain or a burning sensation when urinating.
  • Eye infection: The herpes simplex virus may spread to the eyes, resulting in possible pain, discharge and light sensitivity. If left untreated, the infection can lead to scarring on the outer layer of the eye. The infection is sometimes referred to as keratitis and occurs in less than five percent of cases.

After the initial infection, herpes simplex can exist in a dormant (latent) state, wherein no symptoms present themselves but the virus is still present within the body. Latent herpes simplex can reactivate because of a number of factors, including:

  • Fever
  • Menstruation
  • Emotional stress.

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Read more about Signs of Herpes »

Causes of herpes simplex

Herpes simplex is transmitted through skin to skin contact between an individual infected with the virus and an individual who is not. The carrier of the infection does not need to have symptoms of the infection in order for it to be transmitted. The infection is highly contagious.

Oral herpes commonly develops, especially in children, through activities such as kissing or sharing eating utensils or toothbrushes. Genital herpes is typically transmitted through sexual activity, including:[3]

  • Unprotected sex (vaginal or anal)
  • Sharing sex toys
  • Close genital contact.

It is also possible for mothers to pass on the herpes simplex virus to their child during birth.

Diagnosing herpes simplex

The most common method for diagnosing herpes simplex of both types is a physical examination. A doctor will examine the blisters and sores, inquire about other symptoms, and will generally be able to make a diagnosis on the basis of these.

To confirm the presence of the virus, a laboratory test, known as a herpes viral culture of lesions test, can also be performed. To do so, a sample of fluid is taken from the sores and sent to a lab for testing.[4] Tests are also available to differentiate between herpes simplex virus one and two, including immunofluorescence staining and the immunoblot test (IgG).[5]

If there are no visible symptoms of the virus, blood tests can be ordered to diagnose an infection with the herpes simplex virus. This is known as a serum herpes simplex antibodies test. After taking blood, the sample will be sent to a laboratory and be tested, not for the virus itself, but for the presence of the antibodies produced by the body to fight the virus.[6]

Treatment of herpes simplex

There is no cure for the herpes simplex virus. However, treatments aimed at lessening the symptoms and controlling recurrent outbreaks are available.

The most common treatment method is the use of antiviral creams and ointments. To be most effective, the creams and ointments should be used as soon as the symptoms of herpes appear. The affected area should be kept clean and dry, and no other lotions or ointments should be applied unless they are recommended by a doctor.

If the herpes sores are occurring frequently, it may be advised to use the treatments everyday, even when no visible symptoms are present. This is known as suppressive therapy. Medications are usually used for suppressive therapy, the most common being:[7]

  • Acyclovir
  • Valacyclovir
  • Famciclovir

Read more about treatment for oral herpes »

Herpes simplex prevention

Herpes simplex is most commonly spread by skin to skin contact, as well as through objects that have been in contact with herpes sores. Those that have been infected with the virus should take a number of measures to lessen the risk of transmitting herpes simplex. These include:

  • Avoid kissing during an outbreak, when the chances of transmitting the virus are highest
  • Avoid sharing things such as toothbrushes and eating utensils
  • Avoid touching the sores (if impossible, ensure the hands are thoroughly washed before coming into contact with anyone else).

To reduce the risk of spreading or contracting genital herpes, the most effective method is to use a condom during vaginal, oral and anal sex. Condoms, however, do not cover all parts of the genital area, meaning they do not guarantee full protection.[8]

During an outbreak of the virus, sexual activity should be avoided completely, as this is when the chances of transmitting the virus are highest. Sharing sex toys should always be avoided. Complete protection against the virus can only be guaranteed through full abstention from sexual activity.

Herpes simplex prognosis

In otherwise healthy children and adults, herpes simplex rarely leads to any severe complications. However, newborn babies and people with weakened immune systems can suffer severe and serious complications. One complication that has been linked to herpes simplex is encephalitis, a rare but potentially life-threatening condition affecting the brain.[9]

When newborn babies or people with weakened immune systems show symptoms of the virus, professional medical attention should be sought quickly.

In all cases, the virus never leaves the body and may lay dormant indefinitely. The first outbreak (the primary outbreak) is generally the most aggressive, with recurrences typically milder and less painful.[9]

Herpes simplex FAQs

Q: Can I catch herpes on parts of the body that aren’t the mouth or genitals?
A: The herpes simplex virus normally affects either the mouth (type one) or the genitals (type 2). However, though rare, the virus can also affect other parts of the body such as:

  • The fingers (known as herpetic whitlow)
  • The nipples
  • The arms

When this happens, the virus is normally spread from the mouth or genitals.

Q: Can I pass on herpes simplex when displaying no symptoms?
A: Yes. Even when the virus is dormant, it can still be passed on. However, this is less likely than when physical symptoms are present.[10]

Q: Can I catch genital herpes from kissing on the mouth?
A: This is unlikely. Kissing can transmit the herpes simplex virus type 1, which can cause both oral and genital herpes. However, kissing on the mouth will not cause the development of symptoms on the genitals.

Other names for herpes simplex

  • Herpes
  • HSV

  1. WebMD. “Herpes Simplex: Herpes Type 1 and 2.” September 8, 2016. Accessed: July 10, 2017.

  2. American Academy of Dermatology. “Herpes Simplex: Signs and Symptoms.” Accessed: July 10, 2017.

  3. Medical News Today. “Herpes: Causes, Symptoms, and Treatments.” December 16, 2016. Accessed: July 10, 2017.

  4. Medline Plus. “Herpes viral culture of lesions.” September 26, 2015. Accessed: July 10, 2017.

  5. STD Check. “Everything About Herpes 1 & 2 and HSV Testing.” July 31, 2015. Accessed: July 10, 2017.

  6. Healthline. “Serum Herpes Simplex Antibodies Test.” January 19, 2016. Accessed: July 10, 2017.

  7. MSD Manual Consumer Version. “Herpes Simplex Virus Infections.” Accessed: July 10, 2017.

  8. Planned Parenthood. “How is herpes prevented?” Accessed: July 10, 2017.

  9. American Academy of Dermatology. “Herpes Simplex: Diagnosis and Treatment.” Accessed: July 10, 2017.

  10. Herpes Viruses Association. “Frequently Asked Questions.” Accessed: July 10, 2017.

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