Herpes Simplex

Herpes Simplex

Definition/diagnostic criteria

Genital herpes simplex virus (HSV) infection is a common sexually transmitted infection, primarily caused by HSV-2, and to a lesser extent HSV-1. Diagnosis is clinical but can be confirmed by laboratory tests, including polymerase chain reaction (PCR) testing and serology.

Epidemiology

Genital herpes is prevalent worldwide, with variations in incidence across different regions and populations. In the UK, the rate of new diagnoses has been stable in recent years, but the condition remains a significant public health concern due to its recurrent nature and implications for sexual health.

Diagnosis:

Clinical features

Classic manifestations include painful blisters and ulcers on the genitalia, dysuria, and inguinal lymphadenopathy. Atypical presentations may occur.

Investigations

PCR of swab samples from lesions is the gold standard. Serological tests may help in asymptomatic individuals or when PCR is negative, but their routine use is not recommended.

Treatment

Ideally the patient should attend a specialist sexual health service for diagnosis, testing for other STIs, treatment and contact tracing. Antiviral therapy with aciclovir, valaciclovir, or famciclovir is effective in reducing symptoms and transmission risk. Treatment can be episodic or suppressive, depending on the frequency and severity of episodes.

Prognosis

While incurable, genital herpes can be managed effectively with antivirals and supportive measures. Patient education on transmission, recurrent episodes, and implications for sexual health is crucial.

Non-Genital Herpes Simplex

Definition/diagnostic criteria

Non-genital herpes simplex infections include orolabial herpes (cold sores) primarily caused by HSV-1 and herpetic whitlow, among others. Diagnosis is typically clinical but can be confirmed by PCR or direct fluorescent antibody testing.

Epidemiology

HSV-1 infections are highly prevalent in the UK, affecting a large proportion of the population. Transmission is usually via non-sexual contact and often occurs in childhood.

Diagnosis

Clinical features

Orolabial herpes presents as vesicles on the lips and perioral skin. Eczema herpeticum, a severe complication, occurs when HSV infects areas of eczema or damaged skin.

Investigations

Usually no investigation is needed. Otherwise, as in genital herpes, PCR is the diagnostic test of choice for lesions, while serology can be considered in specific cases.

Treatment

Local symptomatic treatment with antiviral creams or systemic antiviral medication for severe cases. For eczema herpeticum, systemic antivirals are indicated, and high-dose treatment may be required.

Children with eczema are at risk of eczema herpeticum if exposed to HSV. Advice includes avoiding direct contact with cold sores, using antiviral treatment promptly if HSV infection is suspected, and seeking urgent medical advice if eczema herpeticum is suspected (PCDS).

Ocular herpes simplex requires urgent ophthalmological review.

Prognosis

Non-genital herpes simplex infections are typically self-limiting but can cause significant morbidity in cases of eczema herpeticum or when infections are recurrent.