Introduction

Learning objectives

Recognize the clinical stages of syphilis and the presentation of the syphilitic chancre.
Recognize the typical presentation of genital herpes.
Use the painful/painless guide without replacing microbiological or serological diagnosis.

Video lesson

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Video pending upload (embedded YouTube)

Summary

A genital ulcer calls for a differential diagnosis.

Two especially important STIs are:

syphilis;
genital herpes.

Syphilis

It is caused by Treponema pallidum.

The disease has different clinical stages.

Primary syphilis

The classic manifestation is the syphilitic chancre. It is traditionally described as:

an ulcer;
usually painless;
with well-defined borders;
sometimes accompanied by regional lymphadenopathy.

But presentations can vary.

Secondary syphilis

It can cause systemic and skin manifestations.

A classic feature is the appearance of lesions that can involve the palms of the hands and the soles of the feet.

Diagnosis

Serologic tests are used, combining treponemal and nontreponemal tests according to the diagnostic algorithm in use.

Treatment

Penicillin continues to play a key role in the treatment of syphilis.

Genital herpes

It is caused mainly by herpes simplex virus.

It may present with:

grouped vesicles;
painful ulcerations;
burning;
pruritus;
dysuria;
lymphadenopathy.

A useful teaching distinction

Classic primary syphilis → ulcer, usually painless.

Classic genital herpes → vesicles/ulcers, usually painful.

This serves as a guide, but it does not replace microbiological or serological diagnosis when appropriate.

Key concept

Not every genital ulcer is herpes, and not every painless ulcer is necessarily syphilis.

PDF

⬇ Download lesson summary

Downloadable PDF pending upload.

Practical algorithm

Urethral discharge + dysuria → think of urethritis → gonococcus/Chlamydia among the main causes.
Painless genital ulcer → consider syphilis.
Painful vesicles or ulcers → consider genital herpes.
Anogenital warts → consider HPV/condylomata.
Epididymal pain in a sexually active patient → consider STIs depending on age and context, but rule out torsion in an acute scrotum.
Diagnosis of an STI → consider testing for other STIs + partner management + prevention.
Recent high-risk HIV exposure → promptly assess the indication for PEP.

An STI is not managed only by treating the patient. The approach includes correct diagnosis, screening for coinfections when appropriate, partner management and prevention of further transmission.

Clinical case

Content pending upload Progressive clinical case focused on decision-making.

Self-assessment

Questions pending upload 5–10 multiple-choice questions on this lesson.

References

Links pending upload References to PubMed, DOI, scientific society guidelines and journals.

Genital ulcers: syphilis and herpes