Herpes simplex is a viral infection caused by the herpes simplex virus. Infections are categorized based on the part of the body infected. Oral herpes involves the face or mouth. It may result in small blisters in groups often called cold sores or fever blisters or may just cause a sore throat. Genital herpes, often simply known as herpes, may have minimal symptoms or form blisters that break open and result in small ulcers. These typically heal over two to four weeks. Tingling or shooting pains may occur before the blisters appear. Herpes cycles between periods of active disease followed by periods without symptoms. The first episode is often more severe and may be associated with fever, muscle pains, swollen lymph nodes and headaches. Over time, episodes of active disease decrease in frequency and severity. Other disorders caused by herpes simplex include: herpetic whitlow when it involves the fingers, herpes of the eye, herpes infection of the brain, and neonatal herpes when it affects a newborn, among others.
Human herpes virus 3 (HHV3) is also called varicella-zoster virus. HHV3 causes chickenpox. It can also cause a recurrent virus infection of the skin, which is called herpes zoster or shingles. Shingles occurs when dormant varicella-zoster virus from an initial bout of chickenpox becomes reactivated. Like its close relative, HHV1, herpes zoster likes to infect skin cells and nerve cells. This virus may also recur along nerve fibre pathways, causing multiple sores where nerve fibres end on skin cells. Because an entire group of nerve cells is often affected, shingles is generally much more severe than a recurrence of herpes simplex. The lesions generally appear in a band-like or belt-like pattern occurring on one side of the body and are often accompanied by itching, tingling, or even severe pain. Healing usually occurs in 2 to 4 weeks, and scars may remain. Postherpetic neuralgia is a complication of shingles where the pain associated with the infection can persist for months and even years. Most people who experience shingles once do not experience it again.
During these periods, it is especially important to abstain from kissing and any form of physical contact with the blistering area, saliva, or sexual discharge. If you are infected, be sure to wash your hands after touching an infected area on either the oral or genital regions. Herpes medications can also help reduce your risk of transmitting the virus to another individual.
Worldwide rates of either HSV-1 or HSV-2 are between 60% and 95% in adults. HSV-1 is usually acquired during childhood. Rates of both increase as people age. Rates of HSV-1 are between 70% and 80% in populations of low socioeconomic status and 40% to 60% in populations of improved socioeconomic status. An estimated 536 million people worldwide (16% of the population) were infected with HSV-2 as of 2003 with greater rates among women and those in the developing world. Most people with HSV-2 do not realize that they are infected. The name is from Greek: ἕρπης herpēs which means "to creep", referring to spreading blisters. The name does not refer to latency.
Herpes simplex viruses -- more commonly known as herpes -- are categorized into two types: herpes type 1 (HSV-1, or oral herpes) and herpes type 2 (HSV-2, or genital herpes). Most commonly, herpes type 1 causes sores around the mouth and lips (sometimes called fever blisters or cold sores). HSV-1 can cause genital herpes, but most cases of genital herpes are caused by herpes type 2. In HSV-2, the infected person may have sores around the genitals or rectum. Although HSV-2 sores may occur in other locations, these sores usually are found below the waist.
Although it’s not caused by either the HSV-1 or HSV-2 virus, herpes zoster falls under the umbrella of herpes diseases. Also known as shingles, it’s an infection caused by the varicella-zoster virus, and is characterized by the development of painful skin rashes on one side of the face or body.23 These rashes are red patches of fluid-filled blisters that tend to crack easily.24,25
Herpes sores follow a similar cyclical pattern and appear first like pimples that turn into small vesicles. Then, the skin becomes crusty, and eventually a scab is formed. It can take up to several weeks for the lesions to heal, during which time there may be one outbreak followed by another. Certain risk factors may increase the likelihood of an outbreak, such as: asthma medication, lack of sleep, stress, decreased immunity and ultraviolet rays.
The U.S. Centers of Disease Control and Prevention explains that pain, itching or tingling in the area where the rashes will eventually appear will occur at least one to five days before the rashes are seen. Once these rashes are visible, they scab for around seven to 10 days and heal within two to four weeks.29 Aside from rashes, symptoms of shingles include fever, chills, headaches, fatigue and an upset stomach.30,31
The causes of reactivation are uncertain, but several potential triggers have been documented. A 2009 study showed the protein VP16 plays a key role in reactivation of the dormant virus. Changes in the immune system during menstruation may play a role in HSV-1 reactivation. Concurrent infections, such as viral upper respiratory tract infection or other febrile diseases, can cause outbreaks. Reactivation due to other infections is the likely source of the historic terms 'cold sore' and 'fever blister'.
According to Cullins, there are no standardized guidelines from the CDC for suppressive therapy through medication, but it is an option that people with HSV should talk to their healthcare providers about. “If a person knows they have had herpes in the past that has affected their genitals, they can take suppressive therapy — for example, 500 mg of valacyclovir daily.” While it won’t prevent outbreaks, it will prevent asymptomatic virus shedding. Preventing exposure to the virus through both medication and a physical barrier can be very effective.