HERPES GENITALIS (HSV-2)
Herpes genitalis, or genital herpes, is a common sexually transmitted disease caused predominantly by herpes simplex virus type 2 (HSV-2), but can also be caused by HSV-1.
Herpes genitalis is a recurrent vesicular eruption of the skin and mucosa in the region between the navel and the buttocks, usually preceded by prodromal symptoms including itching, burning, and tingling.
Primary infection may have associated influenza-like systemic signs, including fever, headache, malaise, and myalgia, which occur 2–20 days post exposure. Tender lymphadenopathy may also develop in the second and third weeks.
In general, recurrences lack systemic symptoms and are less severe than the primary outbreak. Lesions of recurrences occur in the same area but are fewer in number and heal more quickly. Typical lesions of recurrent outbreaks manifest as grouped papules on an erythematous base which progress to thin-walled vesicles, ulcers, and then soft crusts. Dry crusts form in 3–4 days, allowing for healing. Residual hypopigmentation, hyperpigmentation, and scarring may occur with healing.
As no cure exists for herpes genitalis, treatment is aimed at reducing the number of recurrences using suppressive therapy and at promoting rapid healing when a recurrence is present.
Furthermore, treatment aims to reduce infectivity by reducing viral shedding, and to reduce complications such as urinary retention and aseptic meningitis. In the past, aciclovir, both topical and oral, was used as a first-line treatment for recurrences. Given aciclovir’s low bioavailability, it requires frequent dosing.
In the past, the standard dosing of oral aciclovir for a recurrence is 200mg five times daily for 5 days. Alternative regimens have also been shown to be effective, including 400mg three times daily for 5 days, 800mg three times daily for 2 days, and 800mg twice daily for 5 days.
The frequent dosing of aciclovir led to the development of valaciclovir and famciclovir (the prodrugs of aciclovir and penciclovir, respectively) as alternative therapies with improved bioavailability.
The use of topical aciclovir should be discouraged as it is less effective than oral aciclovir.
It has also been demonstrated that valaciclovir is effective when dosed 500mg twice daily for 3 days or 1000mg once daily for 5 days. A dosing regimen of oral valaciclovir, given 2000mg twice daily for 1 day, has been studied and shown to be more convenient; however, further comparative studies are needed. Famciclovir is effective when prescribed as 1000mg twice daily for 1 day. It may also be taken as 125mg twice daily for 5 days. Aciclovir, valaciclovir, and famciclovir may all be used for suppressive therapy.
Immunocompromised individuals have more frequent recurrences and can develop more severe lesions, thus requiring longer treatment periods with higher doses than those used in the immunocompetent. Severe cases may require intravenous therapy. Suppressive dosage regimens have been used in this population. Long-term therapy may lead to the selection of resistant strains of virus. In aciclovir-resistant cases, intravenous therapy with foscarnet may be required.
Another important aspect of genital herpes management is psychosocial. The recurrent nature of genital HSV infection can have severe emotional and psychological impact on patients. Counselling serves to help them cope with the infection and to prevent sexual and perinatal transmission. A physician can empower patients, allowing them to better manage the disease by educating them about the disease process.