Genital herpes

Genital herpes is caused by the herpes simplex virus, of which there are two types. It produces sores or small splits in the skin around the genitals or anus, usually in episodes separated by long quiet periods, and it is among the most common infections there is.

Two facts are worth having before anything else, because together they change the shape of the subject.

Most genital herpes in the UK is now caused by HSV-1 — the same type that causes cold sores — rather than HSV-2, which used to predominate. It is especially the commoner cause in younger people, and it generally arrives through oral sex from someone who has the virus around their mouth, often without knowing.

Only about a third of people who acquire HSV-2 notice anything at the time. Most infections pass unrecognised, which is why a first diagnosis so often comes as a surprise to someone in a long relationship, and why it says very little about when or from whom it was acquired.

What it looks like

A first episode is usually the worst one: small blisters that break into shallow, painful sores, often with swollen glands, aching, fever and feeling generally unwell, and sometimes real difficulty or pain passing urine. It settles over two to three weeks.

Later episodes are typically much milder and shorter — a few days, a smaller patch, sometimes just a split or a sore spot — and are often preceded by a warning of tingling, itching or nerve-like ache in the area or down a leg.

Getting a diagnosis

The test is a swab taken from the base of a sore, analysed by PCR, and current UK guidance is that all new diagnoses should be typed to establish whether it is HSV-1 or HSV-2 — which matters, because the two behave differently. Older culture tests are no longer recommended, as they miss roughly a third of cases a swab would find.

A point worth correcting plainly: blood tests are not how this is diagnosed. Antibody testing has a few specific uses — recurring symptoms where swabs keep coming back negative, counselling after a confirmed first episode, and checking a partner who has no symptoms, particularly where a couple is planning a pregnancy. But routine antibody screening of people without symptoms is advised against, because a result cannot say where on the body the virus is, and it causes distress without changing anything.

Sexual health clinics test for everything in one visit, are free, and do not need a referral.

Treatment

A first episode is treated with antiviral tablets started within five days of onset, or while new sores are still appearing — usually a five-day course of aciclovir or valaciclovir. Alongside: salt-water bathing, ordinary painkillers, and topical lidocaine where passing urine is painful. Passing urine in a warm bath or shower helps considerably in the first days.

Recurrences are treated with short courses, often held at home and started by the person themselves at the first sign — one to three days of tablets rather than five. Started early enough, these shorten an episode by a day or two, and up to a third of episodes stop before they properly begin.

Where episodes are frequent, continuous daily treatment is an option. Trials generally studied people having six or more episodes a year, though fewer than that can still be reason enough. It substantially reduces recurrences, reduces the virus being shed when there are no symptoms, and is also offered where the diagnosis itself is causing significant distress. It is normally reviewed after a year, since recurrences often return once it stops.

How it does and does not spread

The virus can be passed on during an episode and also at times when there is nothing to see, through what is called asymptomatic shedding. That shedding is commonest with HSV-2 in the first year after infection and in people who get frequent episodes, and it becomes less common over time. Daily antiviral treatment reduces it by something like eighty to ninety per cent.

Several reassurances are solid:

• It is not spread by towels, bedding, toilet seats, swimming pools or shared crockery. It needs direct skin-to-skin contact.
• A partner who already has the same type cannot catch it again.
• Condoms reduce transmission substantially — the measured reduction from men to women is high — though they do not eliminate it, since they do not cover every area involved.
• Episodes become less frequent for most people over the years. After a symptomatic first HSV-2 episode the average is around four a year, and HSV-1 recurs about a quarter as often; both tend to settle.

Avoiding sexual contact during an episode and during the warning sensations beforehand is the main practical measure.

Telling partners

This is where older writing on the subject gave advice that was both wrong and unkind, so the position is worth stating carefully.

There is no requirement to contact past partners. Unlike chlamydia or gonorrhoea, herpes is not subject to formal partner notification as a public health measure, and clinics do not ask people to work back through a history.

Telling a current or prospective partner is a different matter, and is encouraged — not as an obligation imposed from outside, but because it roughly halves the chance of passing it on, and because it allows decisions to be made together. The legal position on disclosure in the UK is not clearly settled, which is itself a reason to talk to a clinic rather than to guess. Sexual health services do this conversation constantly and will help rehearse it.

Pregnancy

Most people with genital herpes have entirely normal pregnancies and deliveries. The risk to a baby is real but specific, and it is highest in one particular situation: a first episode in the third trimester, in someone who has no existing antibodies to that type. A caesarean is offered in that case, because the chance of passing the virus to the baby during birth is significant.

Where herpes is long-standing and recurrent, the risk at delivery is much lower, and a vaginal birth is usually appropriate, often with antiviral treatment in the last weeks.

Two practical points. Anyone pregnant with herpes, or whose partner has it, should tell the midwife early rather than at the end. And where a pregnant person does not have the virus but their partner does, using condoms or avoiding sex from around two weeks before the third trimester — and during any episode — is the measure that prevents the dangerous scenario arising.

The part that is usually harder than the symptoms

For a great many people the diagnosis lands much harder than the illness does, and that is worth naming rather than skating over. UK guidance now specifically advises clinicians against alarmist framing — against reaching for words like incurable and chronic — because the stigma attached to the word herpes bears no relation to how serious the condition actually is, and because distress of that kind interferes with people taking in what they are told.

What is accurate: it is extremely common, most episodes are minor, they become less frequent, treatment works well, transmission can be reduced a great deal, and it does not affect fertility or long-term health. Antiviral treatment itself reduces anxiety in people who find the diagnosis difficult, which is one of the reasons it is offered for that reason alone. Anyone still distressed by it a year on is entitled to proper counselling, and should ask.

When to be seen

• A first episode, or any new genital sores or splits — for a swab while there is something to swab.
• Inability to pass urine, which occasionally happens in a severe first episode and needs urgent attention.
• Frequent episodes, which is reason to discuss daily treatment rather than keep managing them one at a time.
• Pregnancy, or planning one, where either partner has herpes.
• A suppressed immune system, where episodes can be more severe and need treating promptly.
• Sores that are not healing, or that keep recurring with negative swabs — there are other conditions that look similar.

Vulval itching and soreness without sores is more often something else, and the commoner causes are under vaginal thrush. The related but separate condition caused by the chickenpox virus is shingles, which despite the name has nothing to do with this.