Abstract
Genital herpes is a common condition which is caused by the herpes simplex virus (HSV). There are two viral types, HSV1 and HSV2, both of which contribute to oral and genital infections. HSV is readily inactivated at room temperature and by drying, so transmission is by close physical contact, either sexual or genital. Most people acquire HSV subclinically through an infected contact. After the primary infection, the virus lies dormant in local sensory ganglia and reactivates intermittently resulting in lesions or asymptomatic shedding of virus.
The GP curriculum and genital herpes
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manage primary contact with patients who have sexual health concerns and problems elicit appropriate signs and symptoms, arrange subsequent investigation, treatment or refer patients presenting with genital skin conditions, including rashes and ulcers
Clinical features
The majority of patients infected with herpes simplex virus (HSV) are asymptomatic, and clinical presentation varies according to whether an attack is a primary infection or a recurrence. It is important that a history and examination is performed in general practice to exclude other causes of genital ulceration such as Behçets syndrome and dermatitis (see Box 1).
Causes of anogenital ulceration
Trauma Sexually transmitted infections, e.g. anogenital herpes, primary or secondary syphilis, chancroid, lymphogranuloma venereum and granuloma inguinale Non-sexually transmitted infections, e.g. herpes zoster Systemic disease, e.g. Behçets disease, inflammatory bowel disease, erythema multiforme and pyoderma gangrenosum Fixed drug eruptions Dermatological conditions, e.g. lichen planus, lichen sclerosis and cicatricial pemphigoid Malignant dermatological skin conditions, e.g. basal cell carcinoma, squamous cell carcinoma and melanoma
Primary infection
A primary HSV infection usually presents 3–14 days after acquiring the virus and individuals may complain of systemic upset such as fever and myalgia. There can also be local symptoms such as tender inguinal lymphadenopathy and vaginal or urethral discharge. Patients may complain of painful blisters which burst to leave ulcers (Fig. 1) on the external genitalia as well as tingling (neuropathic) pain in the genital area, buttocks or legs. The ulcerated genital herpes lesions can be extremely sore and patients may find it very painful to sit down or micturate. In extreme cases this can result in acute urinary retention. A small number of patients, especially during the primary infection, may present with complications, including secondary bacterial infection, sacral radiculopathy (causing urinary retention and/or constipation) and rarely aseptic meningitis.
Typical skin lesions seen in genital herpes.
Recurrent infection
Recurrent episodes of HSV infection usually occur within the first year and tend to be milder compared to the primary attack. Patients may complain of tingling and burning 48 hours prior to the appearance of lesions. The blisters tend to affect a smaller area than those of a primary infection and resolve fully within 3–4 days.
In patients who present with recurrent infections, it is useful to check how the diagnosis of genital herpes was confirmed, by reviewing swab results and the outcome of any genitourinary medicine (GUM) clinic referral. A history of the current symptoms and appropriate genital examination can assess severity and rule out other diseases.
Investigation and referral
Patients who present with a first attack of HSV should ideally be referred to GUM to confirm the diagnosis, screen for other sexually transmitted infections and follow up. Swabs of the affected area are usually taken in the GUM clinic; however, if there is a delay in referral, then swabs can be taken in a general practice setting and treatment commenced.
There are a variety of diagnostic tests available for detecting HSV. It is important to check which investigations are processed locally because the availability of tests varies throughout the country. In all cases, if there is a delay in the processing of swab results (e.g. over a weekend) and a clinical diagnosis of HSV infection has been made, treatment should be commenced.
Tests available include:
Swabs taken from lesions, especially from vesicle fluid. These can be sent for HSV culture or polymerase chain reaction (PCR). HSV culture has a specificity of nearly 100% but storage and transport conditions affect the yield. HSV PCR is a better investigation; it has less strict storage requirements and increases detection of HSV compared to culture techniques. However, a negative swab or culture result does not exclude herpes infection. Serology testing that detects HSV-specific antibodies. These tests are of limited value as they can be difficult to interpret and may be positive despite a low probability of herpes infection.
Treatment
Primary attack
Ideally all patients with a new diagnosis of genital herpes ideally should be referred to GUM for treatment, education and contact tracing. However, the availability of GUM services varies throughout the country and there may only be a few clinics a week. In addition, many patients feel embarrassed to attend GUM clinics and find it difficult to access this service as a result. These factors limit the number of people attending GUM. Therefore, it may be necessary to commence the initial management and, in certain situations, arrange all treatment within primary care. Genital herpes is a clinical diagnosis and treatment should be started while awaiting swab results or GUM clinic appointment.
Another important aspect of treatment is ensuring adequate analgesia because an acute attack can be very painful. Analgesia usually involves the use of paracetamol, codeine and/or non-steroidal anti-inflammatory drugs (NSAIDs). Ice packs placed over the affected region can also be helpful. Encourage patients to use saline bathing, which will relieve symptoms and promote healing. Topical 5% lidocaine is also valuable especially prior to micturition but should be used with caution because of the risk of potential sensitization.
If a patient presents within 5 days of lesions developing, or beyond 5 days but is still continuing to produce new lesions, antivirals should be started. Antiviral treatment reduces severity and duration of episodes but does not reduce recurrence rate. A 5 day course of systemic (oral) treatment is recommended. Topical antiviral treatment is ineffective.
Three different types of antiviral drugs are currently available (aciclovir, famciclovir and valaciclovir). Evidence from randomized controlled trials shows that all three drugs are equally effective for reducing the severity and duration of genital herpes attacks. However, there is a significant difference in price between the antivirals. At present, aciclovir is recommended because it is the cheapest, but better concordance can be achieved with other antivirals, such as famciclovir, because they have less frequent dosage regimes.
Patients not being followed up by GUM should be followed up routinely after 5 days in primary care. At the follow-up appointment, assess effectiveness of treatment and discuss swab results if these have been taken.
Recurrent episodes
Generally, recurrent episodes are self-limiting and mild. Simple measures such as analgesia and saline bathing are often sufficient to manage these attacks. However, it is important to discuss treatment options with the patient, who may request antiviral treatment. A 5 day course of antiviral medication can be prescribed during each episode but the patient should be informed that these drugs need to be commenced as soon as prodromal symptoms occur and will only reduce the duration of disease by 1–2 days. Patients with recurrent attacks can be taught to self-manage their symptoms and take antiviral treatment as necessary. They do not necessarily need to seek medical advice during each episode.
If an individual is suffering with more than six recurrences per year, consider suppressive treatment. This involves taking antiviral medication for 6–12 months. After this time, antiviral treatment is discontinued to assess recurrence frequency. If there are at least two further recurrences when suppressive treatment has been discontinued, it can be restarted. If there are recurrences despite being on treatment, then the dose of antiviral drugs is increased.
Counselling
A diagnosis of genital herpes infection can cause significant distress. Often there is misinformation about this condition and counselling provides an opportunity for education. Counselling should be provided to all new patients but may also be useful to patients who present with recurrent attacks. Ideally, counselling should be provided by specially trained staff with access to a wide variety of support resources within a GUM clinic setting. However, patients may not want to visit this service, so advice should also be available in general practice.
Counselling on sexually transmitted infections within the general practice setting can be challenging. Barriers include time constraints and concern about confidentiality especially if other family members or partners are registered within the practice. Disclosure to partners is often a difficult issue for patients but is more likely to happen in the context of an ongoing relationship. On discussion with the patient it is important to address what they understand about the implications of the diagnosis and future management. The distressing nature of symptoms and the stigma associated with HSV infection, as with other conditions, often results in impaired information retention.
A primary attack does not necessarily indicate recent infection because HSV infection could have been acquired years previously. HSV infection may therefore not necessarily be due to an unfaithful partner. Patients should be informed that they may have been infected asymptomatically, and partners can pass on the virus without their knowledge through asymptomatic viral shedding. The risk of viral shedding is increased when symptomatic, therefore patients should be advised to abstain from sexual contact while lesions are present. Additionally, the use of condoms does not offer full protection against infection due to close skin contact or contact with infected secretions during foreplay.
Advise patients that following an acute attack there may be recurrent episodes (on average four to five attacks over 2 years). Following this, recurrent attacks are less frequent. There is no cure for genital herpes but treatment involves symptom control and the use of antivirals if needed. Patients also should be advised that due to the method of transmission of genital herpes, they should also be tested for other infections, ideally within the GUM setting. Information about support groups such as Herpes Viruses Association is useful and can be accessed via www.herpes.org.uk.
Herpes and special groups
Pregnancy
The management of genital herpes in pregnancy can be categorized into primary and recurrent episodes. However, accurate clinical classification into these two groups can be difficult and all pregnant women with genital ulcers should be referred to GUM or an obstetrician for diagnosis and advice. The main concern is transmission of herpes infection to the neonate, which is associated with a high morbidity and mortality.
Primary genital herpes infection in the first or second trimester is associated with increased risk of miscarriage. Treatment is usually with oral or intravenous aciclovir, which reduces viral shedding and duration and severity of symptoms. Although aciclovir is not licensed for use in pregnancy, studies have shown no increased risk of teratogenicity. However, pregnant women must be informed of this when prescribing aciclovir.
The main risk factor for neonatal herpes is transmission during delivery. Caesarean section should be offered to all women presenting with primary genital herpes at the time of delivery, or within 6 weeks of the expected date of delivery or onset of labour. In these cases, the risk of neonatal transmission is high if vaginal delivery occurs due to viral shedding and the lack of time for maternal antibodies to be produced and cross the placenta.
Recurrent episodes of genital herpes during pregnancy are usually of short duration and rarely require antiviral treatment. In women with recurrent herpes, maternal antibodies to HSV are already present and cross the placenta to the foetus, therefore reducing the risk of neonatal infection. Consequently, Caesarean section is not routinely recommended for women with recurrent lesions at onset of labour. However, it is important to counsel the woman about the risks of transmission and risks and benefits of each mode of delivery.
Human immunodeficiency virus
Herpes is the most common sexually transmitted infection in human immunodeficiency virus (HIV)-positive individuals. Herpes may also activate HIV replication and increase HIV transmission to other sexual partners. Unfortunately, HIV-positive patients are usually resistant to antiviral medication and are at an increased risk of developing severe complications such as pneumonia, neurological and disseminated disease. Recurrent episodes are likely to present when the CD4 count is low. Therefore, prompt treatment is required and should be managed in a GUM setting.
Key points
Herpes infection is due to HSV1 or HSV2, which is spread by mucosal or sexual contact Patients may be asymptomatic. If it is a primary attack, then patients may complain of painful blisters and neuropathic pain. If it is a recurrent attack, then symptoms are usually milder. Antiviral medication can be used during each attack. It is important to prescribe sufficient analgesia as an acute attack is very painful. Saline bathing and ice packs can also be used. Patients should ideally be referred to GUM for education, contact tracing and to identify other sexually transmitted infections. However, if there is a delay in referral or a patient does not want to attend GUM clinic then they should have swabs and treatment in general practice.