By Dr Ananya Mandal, MD
The treatment of individuals infected with the herpes simplex virus depends on several factors. Some of the factors that determine the intensity of herpes simplex infection and therefore the type of treatment include:
Age of the patient
For example, neonatal herpes is treated in a different way to adult herpes.
Site of infection
Different types of herpes infect different areas of the body and include genital herpes, oral herpes, ocular or eye herpes and herpes encephalitis (affecting the brain). The type of infection determines the priority and setting of treatment. For example, oral herpes may be treated at home while herpes encephalitis may require hospitalization and emergency treatment.
Pregnancy status A woman who is pregnant needs to be screened for the infection before risking transmission to the newborn during childbirth. The mother is at particular risk of transmitting the virus if she has been exposed to it since becoming pregnant. Recurrence status Primary or first-time infection is treated differently to recurrent infection. In the case of primary infection, antiviral tablets containing aciclovir, for example, may be prescribed for five days. In recurrent infection, longer-term treatment lasting 6 to 12 months may be required.
Aciclovir interrupts the DNA multiplication of the herpes viruses. It can be taken five times a day for at least five days or longer if blisters persist or more develop.
Genital herpes can also be treated with other antiviral medications such as valaciclovir or famciclovir. These drugs depend on the viral enzyme thymidine kinase, which converts the drug from its prodrug or inactive form to its monophosphate, diphosphate and finally triphosphate form. The triphosphate form binds to the viral DNA and inhibits replication.
In recurrent cases, treatment depends on the severity of symptoms. In the case of mild symptoms, the area is kept clean using ice packs and petroleum jelly to prevent secondary infections and ease pain. In people with less than six symptom outbreaks per year, a five-day course of aciclovir is prescribed. This is called episodic treatment. In people with more than six recurrent outbreaks per year, aciclovir is given twice daily over a long-term period of 6 to 12 months and this is called suppressive treatment.
Apart from oral treatment, antivirals are also available as topical or locally applied creams or lotions. For example, penciclovir cream can be used to interrupt the multiplication of the virus and although it may not improve existing blisters, it can prevent them from getting worse or lasting as long as they would have done.
An emollient called docosanol can also be used to soothe the skin in patients with oral herpes and is available over-the-counter. Tromantadine is a gel that can inhibit the entry and spread of the virus into the skin cells, through changing the glycoproteins on host cells. Zilactin acts as a protective barrier that "shields" the sore, helping to prevent transmission of the virus.
Reviewed by Sally Robertson, BSc