Genital herpes: diagnosis and treatment

Introduction

Genital herpes is a common sexually transmitted infection caused by the herpes simplex virus (HSV). There are two types of herpes: herpes simplex type 1 (HSV-1) and herpes simplex type 2 (HSV-2)​[1]​.  HSV-1 is the usual cause of herpes around the mouth and lips (orolabial) and now the most common cause of genital herpes in the UK. HSV-2 was historically the most common cause of genital herpes in the UK and the virus type that is more likely to cause recurrent anogenital symptoms​[2]​. 

In the UK, seven out of ten people have contracted at least one type of HSV by the age of 25 years​[1]​. Only one third of individuals will develop symptoms and so most people do not know that they have it​[2]​.

Herpes simplex is part of the herpes virus family that also includes chickenpox and glandular fever. These viruses can remain dormant in the body and may lead to recurring symptoms in the future, which is why they are often referred to as ‘incurable’. However, when symptoms resurface, the immune system works to heal or ‘cure’ them. Typically, herpes simplex infections are localised to a specific area (or dermatome) and do not commonly spread to other parts of the body​[1]​. The focus of this article is primarily on infections in the genital region.

Pharmacists have a role in providing information, support and treatment options for individuals with genital herpes. This article will outline the symptoms and risk factors, diagnosis and management of the condition.

Signs and symptoms

Genital herpes can present with symptoms such as blisters, tingling, itching, and pain in the genital area. This is notably different from the appearance of genital warts, which present as flesh-coloured lumps​[3]​. These symptoms may vary between men and women, with women often experiencing more severe symptoms​[3]​. It is important to note that some individuals may be asymptomatic carriers of the virus​[3]​. The interval between infection and the appearance of symptoms can be between two days and two weeks. Many people may have mild symptoms or no symptoms at all when they are first infected, which can make it difficult to realise they have contracted the virus. Symptoms may not appear for many years, which may potentially cause suspicion of infidelity in a long-term relationship​[1]​.

Some individuals may never experience symptoms at all (known as asymptomatic carriers), while others may initially feel tingling or itching in the genital area. Swollen and sensitive glands in the groin, along with flu-like symptoms, may also occur. Small blisters or ulcers may appear, which can be numerous or there may only be one. These blisters eventually burst, leaving behind small, red, often painful sores that crust over on dry skin and heal within three to ten days​[1]​.

Symptoms of genital herpes can include painful ulceration, dysuria and vaginal or urethral discharge. Systemic symptoms, such as fever and myalgia, are more common in primary infections than in non-primary or recurrent disease. Rarely, systemic symptoms may be the only indication of infection​[2]​.

On examination, signs of genital herpes may include tender swollen lymph nodes around the groin (inguinal lymphadenitis). In first episodes of the disease, lesions and lymphadenitis are typically bilateral. Recurrent episodes may have lesions that affect favoured sites on one side. Lymphadenitis occurs in approximately 30% of patients with genital herpes​[2]​.

Risk factors

The following risk factors can increase the likelihood of contracting the virus and developing symptoms: 

• Oral, anal or vaginal sex without the use of barrier protection (e.g. condom, dental dam);
• Sexual contact with a person with HSV-1 or HSV-2;
• Multiple or anonymous sexual partners;
• Presence or history of another sexually transmitted or blood-borne infection;
• Females are at higher risk of acquiring genital herpes from a male partner than vice versa​[4]​.

Transmission

Herpes is passed directly from the affected area of skin, which could be the genitals, face or hands, by direct skin-to-skin contact with friction when the virus is present. Subsequent outbreaks may return at or near the place the virus was contracted, meaning that if it is contracted, it will not travel through the body and appear on the face or be present in saliva​[1]​.

Transmission is very likely if there are lumps, blisters or sores present, but unlikely when there are no symptoms. It is contracted on the genitals by having sex with someone when the virus is active on their genitals or by receiving oral sex from someone with a facial cold sore. The virus is not contracted from objects such as towels, sheets, cups, cutlery, baths, swimming pools or blood, and it is easier to infect the thin skin of the lips, genital and anal region rather than normal skin​[1]​.

Herpes simplex can easily enter through mucous membranes or through a cut or break in the skin on other parts of the body if there is direct contact with the affected area. In some cases, the virus can enter the body through damaged skin owing to conditions like eczema or sunburn. It is important to avoid skin contact with the affected area when symptoms or warning signs such as itching, stabbing pains, tingling, burning, or aching are present​[1]​.

Using condoms can help prevent transmission if they are put on before any skin contact with the affected area and cover the right area. It is crucial not to allow a sexual partner to come into contact with the affected area during times of symptoms or warning signs to minimise the risk of transmission​[1]​.

Diagnosis

Patients with symptoms of genital herpes typically seek evaluation at sexual health clinics, primary care settings or pharmacies. Diagnosing the condition involves a physical examination, medical history and laboratory tests, such as viral culture or polymerase chain reaction (PCR) testing. Differential diagnoses for genital herpes include conditions such as genital warts, which can be ruled out through visual inspection and testing, or monkeypox, impetigo, scabies, which would require referral to a sexual health clinic or GP​[1]​.

Viral identification techniques such as nucleic acid amplification tests (NAATs) or viral culture are used to diagnose herpes​[4]​.

Confirming the infection and identifying the type through direct detection of HSV in genital lesions is essential for diagnosis and management. PCR is recommended as the preferred diagnostic method for genital herpes owing to its increased detection rates compared to viral culture. NAAT methods are now considered the test of choice for diagnosing herpes. HSV culture is still used in some centres but may miss around 30% of PCR-positive samples​[2]​.

Management

The use of antiviral drugs differs depending on whether the patient is presenting with a first episode of anogenital herpes or a recurrence​[2,5]​. Oral antivirals are indicated if started within five days of the episode but can still be used whilst new lesions are forming or if systemic symptoms persist​[2,5]​. It should be noted that while antiviral drugs can reduce severity and duration of episodes, they do not alter the frequency or severity of subsequent episodes​[2,5]​. 

First episode

• Aciclovir 400mg three times a day orally for five days​[6]​;
• Valaciclovir 500mg twice a day orally for five days​[7]​.

Alternative regimens

• Aciclovir 200mg five times a day for five days​[6]​;
• Famciclovir 250mg three times a day for five days​[8]​.

Topical agents are less effective and there is no evidence to show combining oral and topical treatments is any more effective than oral alone​[2]​. Both aciclovir and valaciclovir demonstrate similar efficacy in suppressing the frequency and quantity of genital HSV shedding; however, valaciclovir demonstrates better absorption and more prolonged serum concentrations​[9]​. Treatment choice should be guided by local formulary restrictions and patient preference regarding frequency of dosing​[5]​.

Recurrent episodes

Whilst recurrent episodes are self-limiting and generally milder than initial presentation, episodic antiviral treatment can be considered: 

• Aciclovir 400mg three times a day for three to five days​[6]​;
• Valaciclovir 500mg twice daily for three days​[7]​;

There is little evidence to suggest an advantage of one treatment over another.

If patients have at least six recurrences per year, suppressive antiviral therapy can be considered. A common regimen is aciclovir 400mg twice daily, increasing to three times a day if breakthrough episodes occur​[5]​. This should be discontinued after a maximum of one year to assess recurrence​[5]​. As recurrence can be triggered by discontinuation, an assessment period should include at least two recurrences before resuming suppressive therapy. Patient-initiated treatment at the first signs of recurrence is most beneficial​[2]​. 

Patient prognosis 

HSV-2 is more likely to cause recurrence of symptoms, with a median recurrence rate of four per year, compared with one per year for HSV-1 and this generally decreases over time. Complications can include superinfection of lesions with streptococcal and candida, neuropathy leading to urinary retention, and aseptic meningitis, but these are rare​[2]​. 

Self-care

Non-pharmacological management, such as saline bathing and use of topical anaesthetics, including 5% lidocaine ointment, can be used in addition to antiviral medication. Patients should be advised to keep sores clean and dry and wear loose-fitting cotton underwear during episodes. Applying petroleum jelly to the sores can be used if urination is painful. For recurrent episodes, it is beneficial for patients to review and address any potential triggers. These may include exposure to UV light, tight clothing, smoking and other factors, such as stress​[10]​.

Sexual activity with the same partner can be resumed when symptoms have improved. For new partners, sex should be delayed until ulcers have fully healed. Patients should be reminded it is still possible to transmit the virus even if no symptoms are showing and using condoms can reduce this risk​[11]​. 

References