Herpetic Neuralgia- A Symptom of Genital HSV Infections?

For nearly 3 years, my patient has had frequent recurrences (now, almost monthly)of erythematous, slightly pruritic lesions on the lower back, inguinal area, orbuttocks--but never on the genitalia. Sometimes the lesions have become vesicular,at which time they have had a herpetic appearance. In addition, on a few occasionsshe has had enlarged tender lymph nodes in the inguinal and neck areasthat resolved after the lesions healed. Her herpes simplex virus type 2 (HSV-2)antibody levels have been elevated for most of this time. I have treated the condition with oral famciclovir or acyclovir.Recently, severe pain developed--with elements of tingling or paresthesia--in the patient's lower back and leg on thesame side as the lesions. The pain was refractory to NSAIDs but was immediately relieved by gabapentin.Was the pain a herpetic neuropathy? If so, how often is this seen in HSV infections? Might this patient have herpeszoster with recurrences? Should I obtain a specimen for culture for HSV? Do you recommend treatment with preventivemedication? Is this a sexually transmitted infection?---- MDThe lesions on this patient's buttocks, lower back,and inguinal area, along with localized tender inguinallymphadenopathy, could be manifestationsof recurrent genital herpes. Cervical lymphadenopathyis an unusual finding in genital recurrences.Other neurologic symptoms of recurrent genitalherpes may include autonomic dysfunction, neuralgia,paresthesias, and dysthesias in the lumbosacral distributionradiating to the legs. The monthly occurrence ofthese symptoms in this patient makes recurrent herpeszoster unlikely.A viral culture of material from the base of a lesion inthe vesicular stage, done when the patient is not beingtreated, could help to diagnose HSV infection. A positiveresult would confirm the diagnosis; however, a negativeresult would not rule it out. In addition, in a patient withfrequent recurrences and inconsistent condom use, considerrepeated HIV testing.Additional HSV type-specific serologic tests (based onglycoprotein G [gG]) can accurately and reliably distinguishbetween antibodies to HSV-1 and HSV-2. FDA-approvedgG-based type-specific commercial tests include theHerpeSelect ELISA, the HerpeSelect Immunoblot, and thePOCket HSV-2.¹ The results of type-specific tests are usuallyreported as "positive" or "negative" rather than as "elevated"(as were your patient's results). Several commerciallyavailable tests not based on gG are inaccurate becauseof extensive cross-reactivity between HSV-1 and HSV-2.²Thus, if not done previously, order a type-specificserologic assay. Results that were positive for HSV-2 antibodywould support the diagnosis of genital herpes. Resultsthat were positive for HSV-1 antibody would notdistinguish between oral and genital HSV-1 infections.However, genital herpes caused by HSV-1 recurs less frequentlythan genital HSV-2 infection and would not beconsistent with this patient's clinical course.If the patient has either a positive culture or antibodiesto HSV-2, an empiric 6- to 12-month trial of suppressivetherapy with one of the available oral antivirals is reasonable(acyclovir, 400 mg bid; valacyclovir, 1000 mg/d; orfamciclovir, 250 mg bid). All 3 antivirals are effective inreducing the frequency of symptomatic recurrences, butacyclovir is the least expensive and valacyclovir offers theconvenience of once-daily dosing. If such a regimen relievesthe patient's symptoms, you could continue suppressivetherapy. Topical antiviral therapy offers minimal clinicalbenefit and is not recommended. This patient is potentiallyinfectious if her partner is seronegative for HSV-2; besure she has received counseling about safe sex.---- Rachna Gupta, MD, MPH
Virology Research Clinic
University of Washington
Seattle

References:

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Ashley RL. Sorting out the new HSV type-specific antibody tests.

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2001;77:232-237.

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Wald A, Ashley-Morrow R. Serological testing for herpes simplex virus(HSV)-1 and HSV-2 infection.

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2002;35:S173-S182.