Genital herpes is a common infection typified by blisters on the genitals and nearby areas. It is caused by the herpes simplex virus (HSV). The herpes virus can impact any mucous membrane on the body; this includes the moist lining of the mouth, where HSV manifests as cold sores.

Genital herpes is most often transmitted through sexual contact, and so is commonly classified as a sexually transmitted infection (STI). Like many STIs, HSV is highly contagious, and can be spread by any direct contact with the affected areas.

Two types of HSV exist, type 1 (HSV-1) and type 2 (HSV-2). Genital herpes is caused both by type 1 and by type 2 HSV.

At first, many people with the herpes simplex virus will not experience symptoms. There can be a gap of months or even years between the initial infection and the first appearance of symptoms. As such, many people are unaware that they have the condition.

If symptoms do appear following the initial infection, they most often become visible between four and seven days following the exposure to the virus. Symptoms of a primary infection tend to be more severe than for a recurrence.

Symptoms of a primary genital herpes infection include:

• Small blisters, which burst to leave open red sores around the genitalia, rectum, buttocks and upper thighs
• Ulcers or blisters on the cervix
• Vaginal discharge
• Pain while urinating
• Flu-like symptoms, including aches and pains

Any of these symptoms can last up to 20 days. When the sores do scab and heal, they will do so without scarring.

When these initial symptoms clear, HSV will remain dormant (inactive) in a local nerve. It may occasionally reactivate, returning to the skin to cause a recurrent outbreak.

Symptoms of these recurrences may include:

• Tingling, burning or itching sensations in the affected areas, in advance of the reappearance of blisters
• Recurrence of red blisters, leaving sores around the genitalia, rectum, buttocks and upper thighs
• Recurrence of cervical blisters and ulcers for women

Frequently, these recurrent outbreaks will be shorter and less severe, because the body will have produced protective antibodies in response to the primary infection. The body now has the appropriate proteins to fight the infection more effectively. Going forward, further recurrences should appear less frequently and be less severe.

HSV can spread in many ways:

• By direct contact with the affected area during sex. This does not require penetrative (vaginal or anal) sex; infection can spread just from close genital contact.
• By contact with the skin if, during sex, skin on which the virus is active is unprotected by a condom or by a latex or polyurethane square.
• When receiving oral sex from a partner with a cold sore. This can occur even if the partner’s symptoms have not yet appeared.
• When touched in the genital, vaginal or anal area by a partner with herpes on the finger or hand.
• By sharing sex toys.

Herpes is most frequently spread either right before, during, or just after an outbreak or recurrence. HSV can be both caught and spread by both men and women. However, it cannot be acquired from baths or swimming pools, from hugging, or from sharing towels, drinks or cutlery.

The factors that cause recurrences of herpes are not fully understood. However, there are various triggers that may cause HSV to reactivate. These can include:

• Friction in affected areas during sexual intercourse
• Being generally unwell
• Stress
• Excessive use of alcohol
• Exposure to ultraviolet light (e.g. sunbeds)
• Surgery on the genital area
• A weakened immune system (e.g. from chemotherapy)

Genital herpes is most often treated with antiviral medication, such as aciclovir and valaciclovir. A local anaesthetic, lidocaine ointment, can also be used on the affected skin.

Upon experiencing genital herpes symptoms for the first time, talk to your GP or visit a local GUM clinic, also known as a sexual health clinic. They will likely prescribe medication such as aciclovir, an antiviral tablet which you will be required to take five times daily. This dose must be continued for at least five days. If new blisters and sores are forming when treatment begins, the prescription will be for a longer period of time. Importantly, aciclovir does not eliminate the virus from the body; it simply prevents it from multiplying.

Possible side effects of aciclovir include nausea and headaches. Your prescription may be for another similar antiviral medication, such as famciclovir or valaciclovir.

With more severe symptoms, antiviral tablets such as aciclovir will again be prescribed. The dosage will be the same as for a primary infection: five times daily for at least five days. Other recommendations include:

• Wash the affected area with plain or salt water. Keeping blisters and sores clean will help prevent them from becoming infected, and may assist in healing.
• Apply something cool and wet to the affected areas, such as an ice pack wrapped in a hand towel. This will help reduce pain and accelerate healing. Ice should never be applied directly to the skin.
• Apply an anesthetic cream (e.g. 5% lidocaine) or a petroleum jelly (e.g. Vaseline) to blisters and sores. This will make passing urine less painful.
• Drink sufficient fluids to dilute urine, in order to reduce pain. Urinating whilst sitting down in a bath or whilst pouring cool water over the genitals may also ease the pain.

If you experience fewer than six recurrences within a year, a GP will likely prescribe episodic treatment. This entails a five-day course of aciclovir each time tingling or numbness occurs, before the full symptoms begin.

Long-term treatment plans for genital herpes involve taking aciclovir every day. This should occur only if you experience more than six recurrences within a year, or if the symptoms are especially distressing or severe.

This is called a suppressive treatment. Its aim is to prevent further outbreaks from developing. Importantly, this treatment can only reduce the chance of HSV being spread to a partner; it cannot prevent infection altogether.

A suppressive treatment will often involve taking aciclovir twice per day for up to twelve months. After this period, aciclovir will only be taken as needed, in episodic treatments. At this stage, outbreaks should be infrequent and mild. If severe outbreaks recur in future, suppressive treatment can be restarted.

Recurrent outbreaks of herpes can occur due to a weakened immune system. This can be an indicator of other viruses, such as HIV. So, if frequent recurrences continue, consider also being tested for HIV.

It is strongly advised to refrain from any sexual activity (i.e. oral, vaginal or anal sex) if there are any indications that an outbreak will soon occur if any symptoms are present, and for one week after all symptoms have gone. This is necessary to prevent the infection from being spread to a partner. Sexual activity whilst having blisters or sores can also delay their healing.

You should seek immediate medical attention following symptoms of a primary infection because herpes is most easily and accurately diagnosed whilst the infection is active.

A doctor or nurse will often diagnose genital herpes by examining the afflicted areas of skin. If possible, they will take a sample of fluid from the affected area, and send it to a laboratory to confirm the presence of HSV. This confirmation will most often take 1-2 weeks. A negative sample does not guarantee the absence of HSV. A full diagnosis will need to be confirmed by future recurrent outbreaks.

This process may include screening for other STIs. If you test positive for an STI, recent sexual partners will also need to be tested. They may require treatment to prevent further spreading of the infection. GUM clinic staff will suggest which of your previous partners require testing.

Genital herpes is especially common in young people aged 20 to 24.

In England in 2013, over 32,000 people were diagnosed with a primary infection of genital herpes at sexual health clinics.

Whilst no cure exists for genital herpes, symptoms can often be managed with antiviral medication. It remains important to contain the spread of HSV by abstaining from sexual activity until all sores have cleared. For added prevention, condom use should continue even after symptoms have cleared.

HSV can cause complications during pregnancy. It can sometimes be conferred to the child near the time of birth.

The risk to the baby is low if the primary infection occurred before the pregnancy. This is because mothers pass protective antibodies to the baby during the final few months of gestation. As a result, the baby will be protected both during birth and for the subsequent months.

Even if genital herpes recurs during the course of the pregnancy, the risk to the baby remains low. As a precaution, aciclovir may be prescribed from week 36 until birth, in order to reduce the extent of symptoms.

The chance of passing on HSV to the baby rises to three per cent if genital blisters and sores are present at the time of birth.

Aciclovir has been approved for use while breastfeeding by the American Academy of Pediatrics. It is present in breast milk, but the amount ingested by the baby is low and safe. Indeed, aciclovir is commonly given to newborns and rarely causes problems.

On average, genital herpes will recur four to five times in the two years following the primary infection. Symptoms, however, will gradually become less severe, and outbreaks will occur less frequently.