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This viral skin infection (full medical name: herpes simplex) is characterized by a painful accumulation of vesicles on top of a reddish patch of skin. There are two subtypes of herpes simplex virus (HSV-1 and HSV-2). The herpes simplex virus retreats after an eruption on the skin into the ganglion of the sensitive nerve, where it can lie dormant and stay for years. It is thought that periods of stress, exposure to sunlight, other febrile illnesses, excessive sports activities and immune suppression cause HSV-1 and HSV-2 to be reactivated.

The 2 Types of Herpes

Herpes simplex virus, type 1 (HSV-1): involves the skin or mucous membranes around the face, such as the lips, the gums, the lining of the oral cavity, the cornea, and nostrils.
Herpes simplex virus, type 2 (HSV-2): involves the skin around the male and female genitals and the anorectal area in homosexual males. HSV-2 also gets transmitted from the female birth canal to the fetus and can cause severe systemic herpes simplex infections including encephalitis and aseptic meningitis in the newborn. HSV-2 can also cause a lumbosacral myeloradiculitis, which is associated with bladder retention and severe constipation.


Herpes simplex of the lip

Herpes simplex of the lip

Signs and Symptoms

There is a prodromal period of less than 6 hours where there is an electrical sensation and burning in the spot of skin, which is about to break open with blisters.

It is during this time that a lip sore can already be treated and further deterioration can possibly be prevented or at least the extent of the breakout can be kept at bay. The vesicles appear then (usually a crop of several) on a patch of red skin. The size of these clusters of vesicles is between 5 mm and 15 mm (about 1/5 to 1/2 inch). As the vesicles are itchy there is a tendency to scratch them open, which releases the virus and causes a burning sensation. After about 1 to 1 1/2 weeks this dries up with a yellowish crust. The virus retreats into the ganglion of the supplying sensitive skin nerve in the depth of the body only to wait for a reoccurrence in the same spot of skin. This is the dormant phase of the disease.

With lesions in the genital areas at the labia of a woman or at the foreskin or shaft of the penis sex would be very painful and should be discouraged to prevent spread of the disease to the partner. Herpes simplex keratitis is an eye infection with HSV, which starts like conjunctivitis with redness in the eye. There is light sensitivity and there might be a foreign body feeling although no dust particle can be found. This condition should be immediately referred to an eye specialist to prevent disasters like corneal perforation from herpes simplex keratitis. Health care workers who get infected while examining patients with herpes simplex can get a herpetic infection of the finger tips, called “herpetic whitlow“.

This is extremely painful as the area from the last joint of the finger to the finger tip is swollen and reddened due to infiltration of herpes simplex into this tissue (see picture 3 below). The virus has gained access through mini abrasions or breaks in the nailfolds. Here are some pictures of herpes infections (use the back arrow in your left upper screen to return to this page):

picture 1: herpes of lip (thanks to for this image)

picture 2: herpes inside mouth

picture 3: herpes around toe nail fold (encrypted page, you may need to click to agree)

Diagnosis and prognosis

There are a variety of methods to diagnose HSV directly. The most specific is a genetic test using a polymerase chain reaction. Most cases of HSV are self limiting, might reoccur a few times at intervals of several months or years, but eventually seem to settle down with increasing antibodies against HSV. However, a small percentage of patients are continuously experiencing recurrent outbreaks every few weeks of labial or genital lesions. In these patients antiviral coverage for a longer period of time would be reasonable. In AIDS patients where the immune system is weakened, antiviral HSV therapy may have to be given continuously.

Herpes treatment

For serious conditions such as HSV encephalitis, meningitis or systemic HSV disease with pneumonia and hepatitis swift intravenous therapy with acyclovir or other antiviral antibiotics must be started. Later when the patient is stable the patient can be switched to oral medication. More local disease in either the genital area or the face is treated with local applications except for the cases with more frequent recurrences. In these patients oral antiviral HSV therapy should be given for a period of time such as 6 or 12 months.

Herpes simplex keratitis is a potentially dangerous eye infection where the cornea could perforate, if not treated properly. An eye specialist should supervise this condition. Trifluridine (brand name: Viroptic ophthalmic solution) is given several times a day. At times the eye-specialist will decide to also treat with oral acyclovir at the same time. Topical corticosteroids are contraindicated (which means forbidden) as this could lead to corneal perforation. Any bacterial superinfection on skin of the genitals or around the face is treated with topical ointment (bacitracin / neomycin). At times oral antibiotics are necessary, if impetigo follows the initial HSV infection.



1.The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999. Chapter 265.

2.James Chin et al., Editors: Control of Communicable Diseases Manual, 17th edition, 2000, American Public Health Association

3.The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999. Chapter 112.

4. The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999. Chapter 115.

5. The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999. Chapter 113.

Last modified: September 1, 2014

This outline is only a teaching aid to patients and should stimulate you to ask the right questions when seeing your doctor. However, the responsibility of treatment stays in the hands of your doctor and you.