Herpes labialis (Oral herpes simplex)

Alternative names:

herpes simplex - oral; cold sore; fever blister

Definition:

An infection caused by the herpes simplex virus, characterizedby an eruption of small and usually painful blisters on the skinof the lips, mouth, gums, or the skin around the mouth. See also herpessimplex.

Causes, incidence, and risk factors:

Herpes labialis (cold sores, fever blister) is an extremelycommon disease caused by infection of the mouth area with herpes simplextype 1. At least 1 out of 1000 people may be affected with this virus. Mostpeople have been affected with the type 1 virus by the age of 20. The initialinfection may cause no symptoms or mouth ulcers. The virus remains inthe nerve tissue of the face. In some people, the virus reactivates and producesrecurrent cold sores that are usually in the same area but are not serious.Herpes virus type 2 causes genital herpes and infection of babies atbirth.

Both viruses are contagious. Contact can occur directly,or through contactwith infected razors, towels, dishes, etc. The herpes viruscan also infect the fetus and cause congenital abnormalities.

The first symptoms usually appear 1 or 2 weeks after contactwith an infected person, or up to as late as 20 or more days afterexposure. The lesions of herpes labialis usually last for 7 to 10 days,then begin to resolve. The virus may become latent, residing in the nervecells, with recurrence at or near the original site. Recurrence is usuallymilder. It may be triggered by menstrual periods, sun exposure, illnesswith fever, or other unknown causes.

Prevention:

Avoid direct contact with cold sores or other herpes lesions.Minimize the risk of indirect spread by thoroughly washing items in hot(preferably boiling) water before re-use. Do not share items with aninfected person, especially when herpes lesions are active. Avoid precipitatingcauses(especially sun exposure) if prone to oral herpes.

Symptoms:

* warning symptoms of itching, burning, increased sensitivityor tingling sensation may occur about 2 days before lesionsappear

* skin lesion/rash

_o located around the lips, mouth, and gums

* small blisters (vesicles), filled with clear yellowishfluid

_o blisters appear on a raised, red, painful skinarea

_o blisters form, break, and ooze

_o yellow crusts slough to reveal pink, healingskin

_o several smaller blisters may merge to form a largerblister

* mild fever (may occur)

Signs and tests:

Diagnosis is made on the basis of the appearance and/orculture of the lesion. Examination may also show enlargement of lymph nodesin the neck or groin.

Viral culture or Tzanck test of the skin lesion may revealthe herpes simplex virus.

Treatment:

Untreated, the symptoms will generally subside in 1 to 2weeks.

Antiviral medications such as acyclovir may be given bymouth. They may shorten the course of the symptoms and decrease pain. Washblisters gently with soap and water to minimize spread of the virus to otherareas of skin. An antiseptic soap may be recommended. Ice or warmth tothe area may reduce pain. Take precautions to avoid infecting others (seePrevention).

Expectations (prognosis):

Herpes labialis usually disappears spontaneously in 1 to2 weeks. It may recur. Infection may be severe and dangerous if it occursin or near the eye, or if it happens in immunosuppressed people.

Complications:

* blindness (herpes infection of the eye is a leadingcause of blindness in the U.S. because it causes scarring of the cornea--thiscan be treated in many cases with a corneal transplant)

* spread of herpes to other skin areas

* secondary bacterial skin infections

* recurrence of herpes labialis

* generalized infection--may be life threatening inimmunosuppressed people, including those with atopic dermatitis, cancer,HIV infections

Calling your health care provider:

Call for an appointment with your health care provider ifsymptoms indicate herpes labialis and symptoms persist for longer than 1or2 weeks.

Also call if symptoms are severe, or if you have a disorderassociated with immunosuppression and you develop herpes symptoms.

Dr. Song's Oral Medicine Forum