Herpes simplex is a common viral infection. It’s most obvious symptom is localized blistering. There are several forms of herpes viruses, each associated with different symptoms.
Herpes labialis (cold sores, fever blisters typically on the lips or in or around the mouth) is associated with HSV-1 (Herpes Simplex Virus type I) infections and is the most common herpes infection. The infection can be spread from someone else with an active infection and it can also be spread from individuals not showing any symptoms. The infections can be primary (first time) or they can be recurrent. The primary infections may be associated with fever, sore throat, malaise, and swollen lymph nodes, and can last 2-3 weeks. The virus can then be dormant in a nerve for a variable amount of time and reactivate leading to recurrent symptoms. Pain, itching, or burning usually precedes the visible vesicle (blister) formation, which then lasts about a week before forming a crust. During this phase, the virus is active for 3-4 days. HSV-2 infections usually cause genital herpes and also have a primary and recurrent phase analogous to the HSV-1 infection. Other herpes infections are less common.
After the primary infection, whether it was obvious or not, there may be no further clinical manifestations throughout the patient’s life. 80% of the population has been infected with the HSV-1 although only 30% ever show signs of an active outbreak. 25% of the population have been infected with HSV-2 virus. More than one third of the world’s population have recurrent clinical HSV infections.
Other types of herpes infections can occur elsewhere on the skin (e.g., the hands and digits) and can occur with people who have eczema, with athletes involved with physical contact (e.g. wrestlers), in pregnant women, in immunocompromised individuals and in newborns. These latter cases, though not common, may have more severe complications.
Appearance of herpes infections: Classic infections appear as vesicles (blisters) on a red base that often ulcerate or crust. When they recur, they tend to do so at or near the same location on the skin. They normally heal in 7-10 days without scarring. Usually, the affected person feels well; others may suffer from fever, pain and enlarged lymph nodes nearby.
Causes of herpes infections: Recurrent herpes labialis due to HSV-1 may be triggered by a febrile illness, exposure to ultraviolet light, trauma, upper respiratory infection, extremes in temperature, hormonal fluctuations, facial/dental procedures, immunosuppression, or emotional stress. Avoidance of known triggers of HSV recurrences, such as UV light and smoking, may diminish the number of outbreaks experienced by an individual.
Diagnosis: Herpes virus can be detected by obtaining a viral culture from skin vesicles. If the culture is taken within the first 48 hours of an outbreak, 80-90% of cultures will test “positive” for the virus. Scrapings of the fluid from a vesicle and blood tests may also aid in the diagnosis of herpes.
Prevention: Because sun exposure often triggers facial herpes simplex, sun protection including sunscreen with a SPF of #30 or higher and protective clothing (e.g. a hat) are important. HSV viral shedding is greatest during an outbreak, but individuals can spread the virus without ever realizing they have the infection. The simplest way to avoid the initial infection from transmission is to abstain from intimate contact with others. Note that pregnant women who have had the virus in the past should consult with an obstetrician.
Treatment: Most herpes virus symptoms are self-limited. Antiviral therapy can shorten the duration of disease and help prevent transmission to another individual. Oral, intravenous, and topical antiherpetic medications are available for treatment of HSV and are most effective if used at the onset of symptoms. Antiviral therapy can stop the herpes simplex virus from multiplying once it reaches the skin or mucous membranes, but does not eradicate the virus from its resting stage within the nerve cells. While the medication may shorten and prevent an attack, a single course cannot prevent future attacks. To prevent frequent attacks, repeated courses or even constant oral medication may be prescribed. Topical creams applied to affected areas can shorten attacks of recurrent HSV if started early enough.