Sexually transmitted infection caused by the herpes simplex virus
Aetiology
HSV-2 more commonly associated with genital herpes but can also be caused by HSV-1
HSV-1 causes genital herpes and additionally it can affect areas around the mouth and nose causing cold sores
HSV-2 also affects the genital and anal areas causing genital herpes
This means that herpes can be spread to the genitalia via skin-to-skin genital contact, penetrative sex or oral sex with someone who suffers from cold sores
Pathophysiology
After infection, the virus travels up the nearest nerve to the ganglion and remains there - explains why the infection can stay dormant for so long, as here it cannot be reached by the immune system
During the reactivation of the virus, it travels back down the nerve onto the surface of the genitals once again to cause a symptomatic outbreak
Clinical presentation
Primary infection
Blistering and ulceration of the external genitalia, blisters are very painful
External dysuria
Vaginal or urethral discharge
Local lymphadenopathy
Fever and myalgia
Recurrent infection
More common with HSV-2
Often overlooked/misdiagnosed
Usually unilateral, small blisters and ulcers
Minimal systemic symptoms, resolves within 5-7 days
Investigations
Viral swab from the open sore
Management
Primary infection
Oral antiviral treatment e.g. aciclovir 400mg x 5/7
Symptomatic treatment
OTC painkillers
Saline bathing
Local anaesthetic gel
Topical lidocaine 5% ointment if very painful
Avoid all sexual contact during an outbreak, as the open sores are the most infective form of HSV
Recurrent outbreaks
Symptomatic treatment as above
If episodes are regular then episodic treatment is recommended - involves taking aciclovir as soon as symptoms begin to present to reduce the severity of outbreaks
If outbreaks become very frequent or are particularly severe then suppressive treatment is recommended - involves taking daily doses of aciclovir to prevent new outbreaks
Management of herpes in pregnancy
Risk of fetal infection is high in primary genital HSV
If first episode in 3rd trimester (within 6 weeks of EDD), need to find out if primary or non-primary due to risk of neonatal herpes