Herpes Simplex Virus Infection

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Initial Episode

Description:

Multiple painful ulcers
Symptoms develop within 9 (usually 3) days of sexual contact. (Delayed symptomatic presentation beyond 4 weeks of initial herpes infection is uncommon)
Localised (sometimes generalised) lymphadenopathy
Severe external dysuria
A severe episode with systemic symptoms (flu like myalgia, headache) is likely to be newly-acquired infection

Diagnosis:

Often clinical. Can usually be confirmed by a positive HSV PCR result (but never excluded by a negative)
Cotton-tipped swab pressed against open lesions, broken off in virus transport medium for detection by PCR of HSV 1 or 2.

Treatment: (Link to LJF)

Aciclovir 200mg x5/day for 5 days or
Valaciclovir 500mg b.d for 5 days, unless symptoms are very mild or lesions are healing at presentation.
If symptoms are very severe or ulceration extensive, consider a 10 day course of therapy.

Advice to patients: the acute episode

Adequate rest, take time off work
Regular Oral analgesia
Drink plenty of fluids (dilute urine rather than avoid drinking to reduce need for urination)
A warm bath containing sodium bicarbonate or salt is soothing
Pass urine in the bath, or with the shower spray directed at the affected area

Notes:

Antiviral therapy of less use if lesions present for >5days, but treatment is indicated if new lesions are appearing at any stage.
Local anaesthetics may be useful in severe cases in women, as a last resort to avoid the need for suprapubic catheterisation. EMLA (Lidocaine/Prilocaine) is useful. Instillagel (Lidocaine/Chlorhexidine) is also antibacterial and is inexpensive.
Consider Admission: If signs of urinary retention, intractable pain, meningitis or pregnancy (1st or 3rd trimester)

Follow Up:

In a severe primary attack review at 5 days to confirm no new lesions appearing. If new lesions are appearing consider a further 5 days of aciclovir.
Otherwise review at 2 weeks with HSV isolation results:
- Full STI screen if deferred at first visit and sexual history indicates a need
- Advice according to HSV type isolated
Advise patient to return in the event of further attack with severe symptoms.
No need to re-attend, or for further treatment, if recurrences are infrequent and/or mild

Information for patients:

The first attack is usually the worst
Stress that although lifelong infection, recurrences can be treated if severe
In most cases, recurrences are an inconvenience but do not require treatment with antivirals
HSV1: 50% chance of recurrence, HSV 2: 89% chance of recurrence in the first year after a symptomatic initial episode
Recurrence rate variable. 2/3 have less recurrences in year 2 than year one, but 1/3 have more. Average decrease in recurrence rate is about 1 (0.8) per year
Median recurrence rate is 4-5 episodes per year for HSV 2, 1 episode per year for HSV1. Draw parallels with cold sores in childhood
Asymptomatic carriage common. About ¾ of new infections are from asymptomatic partners. Only 10% of people with HSV 2 antibodies give a history of genital herpes. No indication of infidelity in long term partner
No effect on fertility. Not a problem in pregnancy unless the primary infection occurs at the time of delivery. Many obstetricians would now allow vaginal delivery during a recurrence
Chance of an asymptomatic female passing HSV to a male partner with whom she has regular unprotected sex is about 1% per year. Transmission rates in other circumstances unknown but likely to be similar
Virus more commonly excreted in the first three months after infection than subsequently
Leaflet - 'What do you know about...genital herpes'

Last Updated on Friday, 01 March 2013 13:35