BASICS
Description
- Chronic, recurrent HSV type 1 or 2 infection of sacral ganglia-innervated areas.
- HSV-1 causes anogenital and orolabial lesions; HSV-2 mainly anogenital.
- Primary episode: no preexisting antibodies; may be asymptomatic.
- First episode, nonprimary: initial genital eruption with preexisting antibodies.
- Reactivation: recurrent episodes.
- Synonym: herpes genitalis.
Epidemiology
- Most infected age: 15-30 years; prevalence increases with age.
- Female > male.
- Higher prevalence in non-Hispanic blacks.
- Estimated 572,000 to 1.6 million new US cases/year; highest in 18-24 years.
- HSV-2 prevalence 10-40% in general population; up to 60-95% in HIV-positive.
- 48% US population HSV-1 seropositive (age 14-49), 12% HSV-2.
- Up to 90% seropositive unaware of infection.
- Globally: HSV-1 infects 3.7 billion, HSV-2 infects 140 million.
Etiology and Pathophysiology
- HSV-1 and HSV-2 are double-stranded DNA viruses, Herpesviridae family.
- Transmission: genital-genital, oral-genital contact, maternal-fetal.
- Incubation: 4-7 days.
- Highest transmission risk with lesions present; asymptomatic shedding also occurs, more with HSV-2.
- HSV infection increases HIV acquisition risk.
Risk Factors
- Age, number of sexual partners.
- History of STIs, especially HIV.
- Early sexual activity (<17 years).
- Partner with HSV.
- Immunosuppression, fever, stress, trauma.
General Prevention
- Barrier contraception.
- Avoid sexual contact during symptomatic phases.
- Abstinence for complete protection.
DIAGNOSIS
History
- Many asymptomatic (74% HSV-1, 63% HSV-2) or unaware.
- Primary episode more severe, longer, with constitutional symptoms.
- Symptoms: multiple genital ulcers, dysuria, pruritus, fever, tender inguinal nodes, malaise, myalgia.
- Recurrent: prodrome (tingling, burning) 2-24h prior; single/atypical ulcer; dysuria; pruritus lasting ~4-6 days.
- HSV-2 causes more frequent recurrences, especially first year.
- Anogenital HSV-1 infections increasing, especially in young women and MSM.
- Less common: constipation, proctitis, stomatitis, sacral paresthesias.
Physical Exam
- Lesions: groin, perineum, anus, vagina, cervix.
- Lesions stages: papular, vesicular, pustular, ulcerated, crusted.
- Inguinal lymphadenopathy.
- Extragenital: meningitis, recurrent meningitis (Mollaret), sacral radiculitis, encephalitis, transverse myelitis, hepatitis.
Pediatric Considerations
- Neonatal infection: 20-50/100,000 live births.
- 80% from asymptomatic maternal shedding during 3rd trimester.
- Transmission risk 30-50% if maternal primary infection near delivery; higher with HSV-1.
- Neonatal HSV high morbidity/mortality.
- Suspect sexual abuse if genital lesions in children.
Differential Diagnosis
- HIV, syphilis, chancroid, herpes zoster.
- Ulcerative balanitis, granuloma inguinale, lymphogranuloma venereum.
- CMV, EBV.
- Drug eruption, trauma.
- Behçet syndrome.
- Ulcus vulvae acutum (Lipschütz ulcer).
- Neoplasia.
Diagnostic Tests
- Laboratory confirmation for atypical/immunocompromised.
- Viral isolation by culture or PCR (prefer PCR—highest sensitivity/specificity).
- Use proper swabs (Dacron/polyester, plastic shafts).
- Culture specificity >99%, sensitivity varies by lesion stage.
- PCR: 98% sensitivity, >99% specificity; mostly for CSF.
- Type-specific serology: Western blot (gold standard), type-specific IgG ELISA.
- IgM testing limited utility.
- Screening generally not recommended for asymptomatic or discordant couples.
TREATMENT
General Measures
- Ice packs, sitz baths, topical anesthetics.
- Analgesics, NSAIDs.
Medications
- Start antivirals within 72 hours of symptoms.
- After 3 days, antivirals may help with new lesions or pain.
- HIV patients require higher/longer dosing.
First Line
| Drug | Primary Episode | Episodic Therapy | Suppression Therapy | Notes |
|---|---|---|---|---|
| Acyclovir | 400 mg PO TID × 7–10 days | 800 mg BID × 5 days / 800 mg TID × 2 days | 400 mg BID daily | Adjust renal dosing |
| Valacyclovir | 1 g PO BID × 7–10 days | 500 mg BID × 3 days / 1 g daily × 5 days | 500 mg - 1 g daily | Prodrug, better bioavailability |
| Famciclovir | 250 mg PO TID × 7–10 days | 125 mg BID × 5 days / 1 g BID × 1 day | 250 mg BID daily |
Severe/Complicated
- IV acyclovir 5-10 mg/kg q8h until improvement; total 10–14 days.
- Immunocompromised may require prolonged/high-dose.
Precautions
- Renal dose adjustment.
- Probenecid can increase antiviral levels.
- Pregnancy: suppression therapy at 36 weeks; C-section if lesions/prodrome at labor.
ISSUES FOR REFERRAL
- Acyclovir-resistant HSV: consider foscarnet or cidofovir (with infectious disease consult).
- Neonatal HSV: IV acyclovir urgently.
- Suspected sexual abuse in children with genital lesions.
ONGOING CARE
Follow-Up
- Usually not required if treated.
- Consider suppression for frequent recurrences.
- Test for HIV/STIs.
Patient Education
- HSV is lifelong; educate on transmission and symptom recognition.
- Avoid sexual contact during outbreaks.
- Viral shedding possible without lesions.
- Condom use reduces HSV-2 transmission.
- Inform partners before sexual activity.
- Notify maternity care providers.
PROGNOSIS
- Symptoms last 3-21 days.
- Recurrence 1-4 episodes/year on average.
- Antivirals reduce shedding, outbreaks, and transmission.
- Neonates/immunocompromised at highest risk for severe outcomes.
COMPLICATIONS
- Psychological: stigma, depression, anxiety.
- Increased HIV risk (2-3 fold with HSV-2).
- HSV meningitis (rare, more common in women).
- Disseminated HSV (especially in pregnancy).
- Hepatitis.
REFERENCES
-
Nath P, Kabir MA, Doust SK, et al. Diagnosis of herpes simplex virus: laboratory and point-of-care techniques. Infect Dis Rep. 2021;13(2):518-539.
-
Rogan SC, Beigi RH. Management of viral complications of pregnancy: pharmacotherapy to reduce vertical transmission. Obstet Gynecol Clin North Am. 2021;48(1):53-74.
CLINICAL PEARLS
- HSV-1 and HSV-2 cause genital herpes; many are unaware of infection.
- Viral shedding occurs without lesions.
- Meticulous condom use reduces transmission.
- Suppressive therapy decreases recurrences and transmission.