Genital Herpes (HSV-2)

Overview


Plain-Language Overview

Genital Herpes (HSV-2) is a common viral infection that affects the genital area and surrounding skin. It is caused by the herpes simplex virus type 2, which is highly contagious and spreads through sexual contact. The infection often causes painful blisters and sores on the genitals, which can recur periodically. Many people with the virus may have mild or no symptoms but can still transmit it to others. The virus remains in the body for life, residing in nerve cells and reactivating under certain conditions. This condition primarily impacts the reproductive and nervous systems and can cause discomfort and emotional distress.

Clinical Definition

Genital Herpes (HSV-2) is a chronic, recurrent infection caused by the herpes simplex virus type 2, a double-stranded DNA virus of the Herpesviridae family. The virus infects the epithelial cells of the genital mucosa and skin, then establishes latency in the sensory dorsal root ganglia. Reactivation leads to recurrent episodes of painful vesicular lesions and ulcerations in the genital area. The infection is transmitted primarily through sexual contact and is a major cause of genital ulcer disease worldwide. Clinical significance includes potential complications such as neonatal herpes, increased risk of HIV acquisition, and psychosocial impact. Diagnosis and management focus on symptom control and reducing transmission risk.

Inciting Event

  • Sexual contact with an infected partner is the primary trigger for HSV-2 transmission.

  • Initial exposure to HSV-2 leads to primary genital infection.

  • Reactivation can be triggered by stress, illness, or immunosuppression.

  • Mucosal microabrasions during intercourse facilitate viral entry.

  • Hormonal changes may influence susceptibility to reactivation.

Latency Period

  • The incubation period from exposure to symptom onset is typically 2 to 12 days.

  • Latency in dorsal root ganglia is lifelong with intermittent reactivation.

  • Recurrent outbreaks often occur within weeks to months after primary infection.

  • Asymptomatic viral shedding can occur during latency without lesions.

  • Latency period allows virus to evade immune clearance.

Diagnostic Delay

  • Initial symptoms may be mild or mistaken for other genital conditions such as yeast infection or bacterial vaginosis.

  • Patients may not seek care due to stigma or lack of awareness.

  • Asymptomatic viral shedding leads to undiagnosed transmission.

  • Misinterpretation of lesions as herpes zoster or chancroid delays diagnosis.

  • Lack of routine HSV testing in genital ulcers contributes to delayed diagnosis.

Clinical Presentation


Signs & Symptoms

  • Painful genital vesicles and ulcers are the hallmark clinical presentation.

  • Burning, itching, or tingling sensation often precedes lesion appearance (prodrome).

  • Dysuria and urethral discomfort are common in urethral involvement.

  • Fever, malaise, and headache may accompany primary infection.

  • Tender inguinal lymphadenopathy is frequently present during outbreaks.

History of Present Illness

  • Patients typically report painful genital vesicles or ulcers preceded by prodromal symptoms like burning or tingling.

  • Primary infection often presents with fever, malaise, and inguinal lymphadenopathy.

  • Lesions evolve from vesicles to pustules and then painful ulcers over 7-10 days.

  • Recurrent episodes are usually milder and shorter in duration than primary infection.

  • Dysuria and urethritis may accompany lesions in males.

Past Medical History

  • History of prior genital herpes outbreaks indicates recurrent HSV-2 infection.

  • Previous diagnosis of other sexually transmitted infections increases risk.

  • Immunosuppressive conditions such as HIV/AIDS worsen disease severity.

  • Use of immunosuppressive medications may precipitate reactivation.

  • No protective immunity after primary infection leads to lifelong susceptibility to recurrences.

Family History

  • No direct heritable genetic predisposition is established for HSV-2 infection.

  • Family members may share similar sexual behavior risk factors.

  • Rarely, familial immunodeficiency syndromes can increase susceptibility to severe HSV infections.

  • Vertical transmission risk is increased if mother has active genital HSV-2 at delivery.

  • No known familial clustering of HSV-2 beyond shared environmental exposures.

Physical Exam Findings

  • Multiple painful vesicles and ulcers on the genitalia, perineum, or perianal area are characteristic.

  • Erythematous base surrounding the vesicles and ulcers is commonly observed.

  • Tender inguinal lymphadenopathy may be present due to regional lymph node involvement.

  • Friable mucosal erosions can be seen in severe cases involving the urethra or cervix.

  • Dysuria and urethral discharge may be noted if the urethra is involved.

Diagnostic Workup


Diagnostic Criteria

Diagnosis is established by identifying characteristic painful vesicular or ulcerative lesions on the genitalia. Confirmation requires detection of HSV DNA by polymerase chain reaction (PCR) from lesion swabs, which is the most sensitive and specific test. Viral culture can also be used but is less sensitive, especially in recurrent lesions. Serologic testing for HSV-2 specific antibodies may support diagnosis in asymptomatic individuals or those with atypical symptoms. Clinical presentation combined with laboratory confirmation is essential for accurate diagnosis.

Pathophysiology


Key Mechanisms

  • Primary infection with herpes simplex virus type 2 (HSV-2) causes lytic replication in genital epithelial cells leading to painful vesicular lesions.

  • Latency is established in the sacral dorsal root ganglia where the virus persists in a dormant state.

  • Periodic reactivation of HSV-2 from latency leads to viral replication and recurrent genital lesions.

  • Local immune response causes inflammation, erythema, and ulceration at the site of viral replication.

  • HSV-2 infection disrupts mucosal barriers, increasing susceptibility to HIV acquisition.

InvolvementDetails
Organs

Sensory ganglia (e.g., sacral ganglia) serve as the reservoir for latent HSV-2 infection and source of viral reactivation.

Skin of the genital area manifests characteristic vesicular lesions during active HSV-2 infection.

Tissues

Genital mucosal tissue is the primary site of HSV-2 entry, replication, and lesion formation.

Nerve tissue is involved as HSV-2 establishes latency in sensory ganglia after initial infection.

Cells

Epithelial cells are the primary site of HSV-2 infection and viral replication in genital mucosa.

CD8+ T cells mediate cytotoxic immune response to control HSV-2 infected cells during outbreaks.

Dendritic cells present HSV-2 antigens to initiate adaptive immune responses.

Chemical Mediators

Interferon-gamma is produced by T cells and helps control HSV-2 infection by activating antiviral pathways.

Tumor necrosis factor-alpha (TNF-alpha) contributes to local inflammation and lesion formation in genital herpes.

Interleukin-2 (IL-2) promotes T cell proliferation during the immune response to HSV-2.

Treatments


Pharmacological Treatments

  • Acyclovir

    • Mechanism:
      • Inhibits viral DNA polymerase after phosphorylation by viral thymidine kinase, preventing HSV-2 DNA replication.

    • Side effects:
      • Nephrotoxicity

      • Headache

      • Nausea

    • Clinical role:
      • First-line

  • Valacyclovir

    • Mechanism:
      • Prodrug converted to acyclovir, inhibiting viral DNA polymerase and blocking HSV-2 replication.

    • Side effects:
      • Headache

      • Nausea

      • Abdominal pain

    • Clinical role:
      • First-line

  • Famciclovir

    • Mechanism:
      • Prodrug converted to penciclovir, which inhibits viral DNA polymerase and viral replication.

    • Side effects:
      • Headache

      • Diarrhea

      • Nausea

    • Clinical role:
      • First-line

Non-pharmacological Treatments

  • Maintain good genital hygiene to reduce irritation and secondary bacterial infection.

  • Use of analgesics and topical anesthetics to relieve pain and discomfort during outbreaks.

  • Avoid sexual contact during active lesions to prevent transmission.

Prevention


Pharmacological Prevention

  • Daily suppressive antiviral therapy with acyclovir, valacyclovir, or famciclovir reduces outbreak frequency and viral shedding.

  • Episodic antiviral treatment at prodrome onset shortens outbreak duration and severity.

  • Antiviral prophylaxis during pregnancy in women with recurrent genital herpes reduces neonatal transmission risk.

  • Topical antivirals are generally ineffective and not recommended for prevention.

  • No vaccine is currently available for effective pharmacological prevention.

Non-pharmacological Prevention

  • Consistent condom use reduces but does not eliminate HSV transmission risk.

  • Abstinence during active outbreaks prevents viral spread to sexual partners.

  • Avoiding sexual contact with partners who have active lesions is critical.

  • Patient education about prodromal symptoms helps reduce transmission.

  • Screening and counseling for HSV and other STIs in high-risk populations.

Outcome & Complications


Complications

  • Neonatal herpes simplex virus infection can occur with maternal genital HSV during delivery.

  • Herpetic meningitis or encephalitis may develop in severe or disseminated cases.

  • Urinary retention due to sacral nerve involvement or severe urethritis.

  • Bacterial superinfection of ulcers leading to cellulitis or abscess formation.

  • Erythema multiforme can be triggered by HSV infection.

Short-term Sequelae Long-term Sequelae
  • Painful genital ulcers causing significant discomfort and dysuria.

  • Secondary bacterial infection of lesions may prolong healing.

  • Systemic symptoms such as fever and malaise during primary outbreaks.

  • Transient urinary retention due to inflammation of sacral nerves.

  • Regional lymphadenopathy causing localized tenderness and swelling.

  • Recurrent genital herpes outbreaks due to viral latency in dorsal root ganglia.

  • Postherpetic neuralgia causing chronic genital pain in some patients.

  • Psychosocial impact including stigma, anxiety, and relationship difficulties.

  • Increased risk of HIV acquisition and transmission due to mucosal disruption.

  • Potential for chronic urethritis or cervicitis with repeated episodes.

Differential Diagnoses


Genital Herpes (HSV-2) versus Syphilis (Primary Stage)

Genital Herpes (HSV-2)

Syphilis (Primary Stage)

Multiple, painful vesicles or ulcers

Single, painless, indurated ulcer (chancre)

Positive HSV PCR or viral culture

Positive treponemal tests (FTA-ABS, TP-PA)

Lesions recur episodically with pain and crusting

Lesion heals spontaneously within 3-6 weeks without scarring

Genital Herpes (HSV-2) versus Chancroid

Genital Herpes (HSV-2)

Chancroid

Painful vesicular lesions that ulcerate

Painful, soft, ragged ulcer with purulent base

HSV-2 identified by PCR or culture

Haemophilus ducreyi identified by culture or PCR

Bilateral, tender inguinal lymphadenopathy without suppuration

Unilateral, painful inguinal lymphadenopathy with suppuration

Genital Herpes (HSV-2) versus Lymphogranuloma Venereum (LGV)

Genital Herpes (HSV-2)

Lymphogranuloma Venereum (LGV)

Painful genital vesicles or ulcers

Small, painless genital ulcer often unnoticed

Tender, bilateral inguinal lymphadenopathy without buboes

Painful, unilateral inguinal lymphadenopathy with buboes

Positive HSV PCR or viral culture

Positive Chlamydia trachomatis serovar L1-L3 PCR or culture

Genital Herpes (HSV-2) versus Candida balanitis

Genital Herpes (HSV-2)

Candida balanitis

Painful vesicular or ulcerative lesions

Erythematous, pruritic rash with white curd-like discharge

HSV-2 detected by PCR or culture

Presence of budding yeast and pseudohyphae on KOH prep

Requires antiviral therapy for symptom resolution

Rapid improvement with topical antifungals

Genital Herpes (HSV-2) versus Behçet Disease

Genital Herpes (HSV-2)

Behçet Disease

Painful genital vesicles progressing to ulcers

Recurrent, painful oral and genital aphthous ulcers without vesicles

Localized viral infection without systemic vasculitis

Systemic vasculitis with multisystem involvement

Positive HSV PCR or viral culture

No specific infectious agent detected; diagnosis clinical

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