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Genital herpes
Genital herpes is caused by HSV-2 and, increasingly in recent years, also by HSV-1; the virus stays latent in sensory ganglia and recurs, and asymptomatic viral shedding is the main route of transmission.
Why it matters in the exam
The exam shows a young woman with painful blisters that broke into small ulcers on the vulva, fever, tender inguinal nodes and difficulty passing urine — a first episode. The question tests diagnosis (PCR from an open lesion), first-episode treatment (valaciclovir 1 g twice daily for 7–10 days), recurrent episodes (short treatment started at the prodrome) and suppressive treatment for frequent attacks (valaciclovir 500 mg once daily). Pregnancy is a central exam point: the highest risk of neonatal herpes is when the mother is infected for the first time near delivery, so suppressive treatment is given from week 36 and caesarean section is done when there are lesions or a prodrome at labour. Remember that type-specific serology helps separate a new infection from a first attack of an old infection, and that immunosuppressed patients may have chronic ulcers and aciclovir resistance. Condoms and suppressive treatment reduce transmission to the partner.
Key points
- Genital herpes is caused by HSV-2 and HSV-1, stays latent in ganglia and recurs.
- Diagnosis is by PCR from an open lesion, and first-episode treatment is valaciclovir 1 g twice daily for 7–10 days.
- Recurrent attacks get short treatment started at the prodrome, and frequent attacks get daily suppressive treatment.
- In pregnancy suppressive treatment is given from week 36, and caesarean section is done when there are lesions or a prodrome at labour.
- Most transmissions happen during asymptomatic viral shedding, and suppressive treatment and condoms reduce transmission.
Summary table
| Setting | Picture | Treatment (CDC 2021) | Note |
|---|---|---|---|
| First episode | Painful blisters and ulcers, fever, inguinal nodes, urinary retention | Valaciclovir 1 g twice daily for 7–10 days, or aciclovir 400 mg three times daily | Start at once, even before the PCR result |
| Recurrent episode | Few lesions, tingling prodrome | Valaciclovir 500 mg twice daily for 3 days, or 1 g once daily for 5 days | Effective only when started early |
| Suppressive treatment | Frequent attacks or wish to reduce transmission | Valaciclovir 500 mg once daily (1 g with very many attacks) | Reduces attacks and transmission to the partner |
| Pregnancy | First infection in the third trimester — highest risk to the newborn | Suppressive treatment from week 36 | Caesarean section if lesions or prodrome at labour |
| Immunosuppression | Chronic, extensive ulcers | Higher doses; foscarnet if resistant | Test for aciclovir resistance |
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Sources
- CDC Sexually Transmitted Infections Treatment Guidelines, 2021 — Genital herpes
- ACOG Practice Bulletin — management of genital herpes in pregnancy, 2020 — Suppressive therapy and delivery
- European guideline for the management of genital herpes (IUSTI), 2017 — Treatment
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.