Genital ulcer disease

Genital Ulcer Disease

Introduction & Australian Epidemiology

Genital ulcer disease (GUD) is a significant public health concern in Australia, particularly affecting sexually active populations and Aboriginal and Torres Strait Islander communities. The spectrum of causative pathogens includes herpes simplex virus (HSV-1 and HSV-2), syphilis (Treponema pallidum), chancroid (Haemophilus ducreyi), and less commonly, Behçet's disease, aphthous ulcers, and lymphogranuloma venereum (LGV).

Australian surveillance data indicates HSV-2 seroprevalence of 12% in the general population, with higher rates among Aboriginal and Torres Strait Islander peoples (20-30%). Syphilis notifications have increased dramatically since 2011, particularly affecting young Aboriginal and Torres Strait Islander people in northern and remote areas. Chancroid remains rare in Australia but sporadic outbreaks occur, particularly in Indigenous communities.

⚠️

HIV Co-infection Risk: Genital ulceration increases HIV transmission risk by 2-5 fold. All patients should be offered HIV testing and counselled about increased transmission risk.

Pathophysiology / Microbiology

Herpes Simplex Virus (HSV)

HSV-1 and HSV-2 are double-stranded DNA viruses. Initial infection involves viral replication in epithelial cells, followed by retrograde transport to dorsal root ganglia where latency is established. Reactivation may be symptomatic or asymptomatic, with viral shedding occurring in both states.

Syphilis (Treponema pallidum)

T. pallidum is a spirochete that penetrates intact mucous membranes or abraded skin. Primary syphilis presents as painless ulceration (chancre) at the inoculation site, typically 10-90 days post-exposure. Without treatment, progression to secondary and tertiary syphilis occurs.

Chancroid (Haemophilus ducreyi)

H. ducreyi is a fastidious gram-negative coccobacillus causing painful genital ulceration with associated lymphadenopathy. More common in tropical climates and areas with poor hygiene.

Clinical Presentation & Diagnostic Criteria

HSV

Herpes Simplex

Primary: Multiple painful vesicles → shallow ulcers, systemic symptoms, bilateral lymphadenopathy
Recurrent: Prodromal tingling, fewer lesions, milder symptoms, unilateral nodes

Syphilis

Primary Syphilis

Single (occasionally multiple) painless, indurated ulcer with clean base and raised edges. Non-tender regional lymphadenopathy.

Chancroid

Haemophilus ducreyi

Painful, deep ulcers with undermined edges, purulent base. Tender, fluctuant inguinal lymphadenopathy (buboes). May suppurate.

Investigations

Essential

HSV PCR from ulcer swab

Gold standard for HSV diagnosis. Type-specific results (HSV-1 vs HSV-2). Available at all public laboratories.
Essential

Syphilis serology (EIA + RPR/VDRL)

Enzyme immunoassay screening with RPR/VDRL titres. Available at all laboratories. Note: May be negative in early primary syphilis.
Specialist

Treponema pallidum PCR

Direct detection from ulcer exudate. Available at reference laboratories (VIDRL, ICPMR). Consider if high suspicion and negative serology.
Specialist

Dark-field microscopy

Direct visualisation of spirochetes. Requires immediate processing. Available at specialist STI centres.
Referral

H. ducreyi culture

Fastidious organism requiring special media. Send to reference laboratory. Low sensitivity (~80%).
Essential

HIV serology + HBV + HCV

Routine STI screen. HIV-1/2 Ag/Ab combo test. Available at all laboratories.
Available

Chlamydia/Gonorrhoea NAAT

First-catch urine or genital swab. Co-infection common. Available at all laboratories.

ℹ️

Diagnostic Approach: Take swabs for HSV PCR from ALL ulcers. Consider syphilis PCR if serology negative but clinical suspicion high. Chancroid diagnosis is often clinical in appropriate epidemiological setting.

Risk Stratification / Severity Scoring

Low Risk

Recurrent HSV in immunocompetent host

Outpatient management, oral antivirals

Moderate Risk

Primary HSV, uncomplicated syphilis

Outpatient management, contact tracing required

High Risk

Immunocompromised, severe HSV, neurosyphilis

Consider hospitalisation, IV therapy, specialist involvement

Very High Risk

HSV encephalitis, disseminated HSV, chancroid with buboes

Hospital admission, IV antivirals, surgical drainage if required

Empirical Antimicrobial Therapy

First-Line Treatment

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Valaciclovir

Valtrex® · First-line HSV therapy

Adult Dose 500 mg BD (recurrent) / 1 g BD (primary)

Paediatric 20 mg/kg BD (max 1 g BD)

Route Oral

Duration 5 days (recurrent) / 10 days (primary)

Renal Adj. CrCl 30-49: 1 g daily; CrCl 10-29: 500 mg daily

Hepatic Adj. No adjustment required

PBS Status ✓ PBS General Benefit

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Benzathine Penicillin G

Bicillin® · First-line syphilis therapy

Adult Dose 2.4 MU (1.8 g)

Paediatric 50,000 U/kg (max 2.4 MU)

Route IM (deep gluteal)

Frequency Single dose

Duration Single dose for primary syphilis

Renal Adj. None required

Hepatic Adj. None required

PBS Status ✓ PBS General Benefit

Second-Line Treatment

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Aciclovir

Zovirax® · Alternative HSV therapy

Adult Dose 400 mg TDS (recurrent) / 400 mg 5x daily (primary)

Paediatric 20 mg/kg QID (max 400 mg QID)

Route Oral

Duration 5 days (recurrent) /

References

01
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12
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National Aboriginal Community Controlled Health Organisation. Aboriginal and Torres Strait Islander Health: Cultural Safety Training Standards. Canberra: NACCHO; 2021.
14
Australian Government Department of Health. PBS Online. https://www.pbs.gov.au/browse/index. Accessed January 2024.
15
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