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Herpes simplex: all you need to know

Marian Nicholson
Herpes Viruses Association

Herpes simplex is extremely common - about 70% of the population has been infected, although only one in five is aware of it. There are two types of herpes simplex:

  • Type 1 is usually a childhood infection: antibodies are found in around 24% of the population by age 14, and 54% by age 30.(1) However, the current prevalence of oral sex means that type 1 now ­causes up to 60% of new cases diagnosed at departments of genitourinary medicine.(2)
  • Type 2 is generally a postpubertal infection, with an infection rate in the UK of between 3% and 25% depending on population tested serologically.(3)

Four out of every five people who carry herpes simplex are unaware that they have it.(4) Due to a reduction of childhood type 1 infection in developed countries, there has been an increase in type 2 infection.(4) This is because having one type gives partial protection against the other type - that is, subsequent infection with the other type is unlikely to show symptoms.

Primary infection - symptoms
Incubation is usually from 2 days to 2 weeks, although it can be much longer (see "Counselling" below).
A primary infection may start with flu-like symptoms. Inguinal glands may be enlarged and tender. Red lumps appear that turn into blisters and ulcers (see Figure 1). On keratinous skin the resultant ulcer will crust over and heal, leaving no scar. The infection lasts from 2 to 4 weeks.


Latency and reactivation
The nine human herpesviruses, which include chickenpox and glandular fever, all have the ability to become latent either in the sensory ganglion of the dorsal root (herpes simplex, varicella-zoster virus) or in the lymphatic system (Epstein­-Barr virus, cytomegalovirus, human herpesviruses 6, 6a, 7 and 8).
After primary infection, the virus will remain dormant in the nearest ganglion: for facial infection this is the trigeminal ganglion, and for anogenital infection the sacral ganglion. When reactivating, the virus can descend any of the sensory nerve sheaths emanating from the ganglion. The trigeminal ganglion serves an area from the jawline to the crown of the head, while reactivation from the sacral ganglion can appear in the anogenital area, the lower buttocks and the back of the legs.
Herpes simplex type 2 is more likely to reactivate when contracted genitally, while herpes simplex virus type 1 reactivates more frequently when contracted facially. Reactivation is often triggered by a lowered immune response due to:

  • Illness (hence the common names "cold sores" or "fever blisters").
  • Tiredness.
  • Trauma to the area.
  • Stress.
  • Sunlight on the affected area.

Herpes simplex is more easily contracted on mucous membranes, but can be caught on keratinous skin through small abrasions. It is transmitted by direct skin-to-skin contact with the affected area (eg, kissing). The virus is fragile and will die below blood heat or when dried, so towels and toilet seats are not sources of infection.
Like all the so-called "childhood diseases", it is only caught once: immunocompetent patients cannot self-inoculate in a different part of the body or reinfect the person from whom they have contracted the virus.(5) In theory, it may be possible to spread the infection around the body during the primary infection; in practice it is unlikely - we do not see toddlers with cold sores that have spread to their hands. The exception to this is eczematous patients (see "Complications" below).
Skin contact with the affected area should be avoided by uninfected partners or family members from the first signs of reactivation. These prodromes can be itching, tingling, burning or aching sensations caused by viral irritation of the affected nerve.
Asymptomatic viral shedding is fairly common for the first 6 months, lessening with time. Two years after infection, the rate of viral shedding averages 2%. This should not prevent normal sociosexual relations (see "Counselling" below).

Herpes simplex is diagnosed by culturing a swab taken from the exudate from a blister or ulcer. Because blood tests for antibodies will usually be positive for herpes simplex type 1, they are not useful to ascertain the cause of genital symptoms.
Differential diagnoses to be considered include herpes zoster, lichen sclerosus, boils, Behçet's syndrome, erosive balanitis, pemphigus vulgaris, syphilis and chancroid. Primary facial symptoms may be confused with impetigo and aphthous ulcers in the mouth.

Primary infection - treatment
Treatment for minor cases is symptomatic: antipyretics, analgesics, topical anaesthetic cream (lignocaine) or soothing treatment (calamine lotion, salt bathing).
More severe cases will need antiviral tablets. This is usually a 5-day course of aciclovir 200mg five times a day. If blisters are still forming, further tablets can be given. Aciclovir cream has such a limited effect that if the herpes is bad enough antiviral tablets should be prescribed.
Severe cases of facial infection may involve the mouth and throat. Ulceration can restrict eating and drinking, and the patient may have to be hospitalised. In the case of genital infection, rarely the sacral nerve is affected and catheterisation may be required.

Recurrent infections - symptoms and ­treatment
Recurrences are nearly always less severe than primary outbreaks: flu-like symptoms are rare, sores heal within 2 weeks.
Treatment is usually symptomatic: analgesics, topical anaesthetic cream (lignocaine) or soothing treatment (calamine lotion, salt bathing). Aciclovir cream has little effect on outbreaks.
Episodic treatment with antiviral tablets is effective  only if the patient is able to start treatment as soon as any prodromal symptoms are detected.
Suppressive therapy may be offered to people who are distressed by too many recurrences (eg, more than six outbreaks a year). Commonly this is aciclovir tablets 200mg three times a day, or 400mg twice a day. However, valaciclovir (Valtrex; Glaxo Wellcome) and famciclovir (Famvir; Novartis) may be prescribed as these are prodrugs with longer bioavailability: tablets are taken only once a day.
The Herpes Viruses Association (HVA) has run several placebo-controlled, double-blind trials. Taking eleutherococcus senticosus (Siberian ginseng 2,000mg) benefited 75% of those on the active capsule versus 35% on the placebo.(6) Siberian ginseng is an adaptogen often used by athletes to enable the body to repair itself more rapidly.
A smaller study by the HVA found that 11 out of 14 people given a 3-month course of olive leaf extract (400mg of 20% oleuropeins) benefited, compared with eight out of 15 taking opuntia streptacantha (extract from the Prickly Pear cactus). In Eastern Europe, olive leaf extract has long been used to treat chronic conditions.


Eczema herpeticum
This is especially prevalent during primary infection. Care must be taken to prevent herpes simplex virus from affecting areas of broken skin. Eczema sufferers are particularly at risk and during a primary infection it can be helpful to bandage any sores/ulcers.

Ocular herpes
This occurs very rarely. When the virus has been caught on the face, it can reactivate inside the eye. This is called ophthalmic herpes simplex or herpes keratitis, dentritis or uveitis. It should be referred to a specialist eye doctor as if left untreated it may damage the eyesight.

Herpes encephalitis
This is extremely rare. During either primary or recurrent episodes of facial infection, the virus can travel to the brain. Headache and "altered lowered consciousness" set it apart from other illnesses. The signs may be so subtle that only people close to the sufferer detect them, and they may have to be very persistent to be taken seriously by health professionals. If untreated, encephalitis may leave damage.

Patients with herpes simplex may have totally unwarranted fears following years of misrepresentation in the media and by comedians. Dispelling some of the most common myths can significantly improve the psychological and therefore physical impact of this skin condition.

Can it spread to other places on my body?
Once the infection is over, antibodies prevent you catching the virus elsewhere on your body. As said previously, we do not see toddlers with cold sores that have spread to their hands.

Can I spread a cold sore to my eye?
As before, if this were possible, it would be common for toddlers to have eye infections. In fact, it is due to the virus using a different route out of the trigeminal ganglion when it reactivates.

Can I give it back to the partner I got it off?
Normally the virus is not caught twice. The person from whom the virus is likely to have been caught is not at risk of reinfection anywhere on the body. And for the same reason, herpes simplex is not recaught by the same person or transferred back to the partner it was caught from.

Am I different from everyone else?
Six out of ten people carry type 1 and one in eight has type 2. Unfortunately, four out of five people do not know they have herpes.

Am I now polluted?
The phrases "you have it for life" and "it is incurable" are particularly damning. Do not use these phrases, and if the patient brings them up explain that chickenpox is for life and the common cold is incurable but nobody bothers to say so as you do not catch them through sex. Telling the patient that we all carry more viruses, bacteria and fungal cells in our bodies than we do cells with our own DNA may allay their fears.

Does this mean my partner has been unfaithful?
Not necessarily. Because the incubation period can be very long, a "nonprimary first infection" may occur years after infection could have taken place. In a sexual relationship, it is more likely that infection is from the current partner, but it is not certain.
The virus may also reactivate after a latency of many years. In a faithful sexual relationship, the appearance of symptoms could therefore be from a reactivation rather than a new infection.

Can I ever have unprotected sex again?
To help the patient, ask if he/she thinks people with cold sores should always kiss through a sheet of cling-film! Between cold sores you tend to forget about them. You can behave in the same manner with genital sores. This reassurance may not be enough for people who have visited websites exaggerating the risks of asymptomatic shedding - where the virus is present on the skin surface without there being any symptoms. This is a new discovery due to more sophisticated tests that can pick up very small amounts of virus. These patients can be told that tests exaggerate the risk by detecting minute quantities of virus too small to infect a person, as well as incomplete viral proteins that cannot multiply. Shedding reduces with time and with the frequency of outbreaks. After 2 years the risk has become 2% on average - comparable to the risk of becoming pregnant while using a condom as a contraception.

Will I need a caesarean section?
Caesarean sections are not needed if you have a ­recurrence.(7) Transplacental immunity provides a full-term, immunocompetent baby with herpes simplex antibodies. To prevent one baby dying of herpes, it would be necessary to do so many caesarean sections that there would be a risk of more women dying from the complications of the section (in itself an extremely rare event in the UK).
A primary infection of herpes simplex on any part of the body during the first trimester may trigger miscarriage, but there are no other sequelae. During the last trimester a primary infection may trigger premature birth, and if the baby comes into contact with the virus the baby is likely to be very ill.

Where can I get more help?
The HVA helpline operates weekdays. All the helpline volunteers are people who have herpes simplex and have been trained to answer questions.


  1. Vyse AJ, Gay NJ, Slomka MJ, et al. The burden of infection with HSV-1 and HSV-2 in England and Wales: implications for the changing ­epidemiology of genital herpes. Sex Transm Infect 2000;76:183-7.
  2. Ross JDC, Smith IW, Elton RA. The epidemiology of herpes simplex types 1 and 2 infection of the genital tract in Edinburgh 1978-1991. Genitourin Med 1993;69:226-8.
  3. Drake S, Taylor S, Brown D, Pillay D. Improving the care of patients with genital herpes. BMJ 2000;321:619-23.
  4. Andria GM, Langenberg A, Corey L, et al. A prospective study of new ­infections with herpes simplex virus type 1 and type 2. N Engl J Med 1999;341:1432-81.
  5. Mindel A, Carney O. Herpes: what it is and how to cope. London: MacDonald Optima; 1991.
  6. Williams M. Immuno-protection against herpes simplex type 11 infection by eleutherococcus root extract. Int J Altern Complement Med 1995;13(7):9-12.
  7. Smith JR, Cowan FM, Munday P. The management of herpes simplex virus infection in pregnancy. Br J Obstet Gynaecol 1998;105:255-60.

Herpes Viruses Association
41 North Road
London N7 9DP
T:020 7607 9661 (ex-directory)
020 7609 9061
The HVA has a counselling card for healthcare professionals - Herpes simplex in a nutshell
You can also send for posters and leaflets
British Association for Sexual Health and HIV (BASHH)