Herpes Simplex (Cold Sores)

Herpes simplex is a viral infection that attacks the skin and nervous system, and usually produces small, irritating and sometimes painful fluid-filled blisters on or around the mouth and nose.


Herpes simplex is caused by a virus, herpes simplex 1 (HSV 1).  After the initial outbreak, the virus usually lies dormant in the skin or in nerve tissue until something triggers another eruption.  Often the trigger is unknown, but in some people overexposure to sunlight, fever, physical or emotional stress, hormonal changes such as pregnancy or menstruation, or certain foods and drugs seem to reactivate the virus.

The first symptoms of a herpes simplex infection usually include burning, tingling or itching sensations around the edges of the lips or nose; this is referred to as a prodromal stage. Within a few hours, small-reddened areas develop followed by the formation of small blisters filled with fluid.  Several small blisters may merge to form a larger one.  As the blisters enlarge, they rupture and leak sticky serum-like fluid, which rapidly crusts.  In uncomplicated cases, the herpes attack usually runs its course in three weeks or less, and seldom leaves a scar.

Image depicting location of cold sore eruption on human face.


Between cold sore eruptions, the herpes simplex 1 virus lies dormant, presumably in the skin or in nearby nerve tissue.

In both the initial and subsequent outbreaks, the blisters and ulcers of herpes simplex are filled with virus and are highly contagious until they heal.  Touching a cold sore and then touching other places can cause the virus to spread to those areas.  To prevent spreading, a person with a cold sore should wash hands frequently especially after contact with the sore, and avoid kissing and oral sex during outbreaks.

Herpes simplex infection of the mouth is very common; and though the appearance may cause concern, it presents no serious risks to your general health.  The main danger involved is spreading the infection to the eye by touching the sore and then touching the eye.  This can cause an eye infection or ulceration of the cornea.  In very rare cases, herpes virus can infect the brain and other parts of the central nervous system, producing meningitis and encephalitis.  This, however, is usually seen only in adults with an immune deficiency disorder.

There is no cure for herpes simplex.  Most mild cold sores clear up on their own and require no treatment.  Over-the-counter cold sore medications can sometimes help reduce the irritation while the sore heals.

Also, your provider may recommend a drying agent to help oozing sores.  If your recurrences are frequent and severe, your provider may prescribe acyclovir, which has been shown to decrease the size and severity of herpes outbreaks.

The herpes virus is always present in the skin or nearby nerve tissue and stays with us for life.  Although you may not always be able to prevent outbreaks, there are some self-help measures that may reduce the frequency of recurrences.  When in the sunlight, use a sunscreen with a minimum protection factor of 15 or a preparation containing benzoic acid.  Practice stress management techniques such as inhalation exercises or progressive relaxation.  Exercise regularly and get adequate rest. The relationship between diet and prevention of herpes simplex is a subject of debate.  It is recommended you discuss current ideology with your provider.

Notify your health care provider if you develop:

Drug Facts & Comparisons. (1996). Antiviral Agent. - page 572
Color Atlas & Synopsis of Clinical Dermatology (1992). - page 70
Clinical Guidelines in Family Practice (1998). - pages 294-295