Syphilis vs. Herpes Simplex: Diagnosing Genital Ulcers in STD Control and Serology

The diagnosis of genital ulcers in medical consultations is a common challenge we face in daily clinical practice. The two most frequent infectious causes of these lesions are syphilis and herpes simplex. Both sexually transmitted diseases (STDs) present clinical and diagnostic characteristics that require a rigorous approach for their identification and proper management.

Diving into Differential Diagnosis

Syphilis, caused by Treponema pallidum, and herpes simplex, typically caused by herpes simplex virus type 2 (HSV-2), are the primary etiologies of genital ulcers. The literature suggests that herpes simplex is the most common cause in the United States, while syphilis has shown a resurgence in various regions worldwide.

The diagnosis of these conditions is based on a combination of clinical evaluation and laboratory tests. For herpes simplex, the recommendation is to perform polymerase chain reaction (PCR) tests to confirm the presence of the virus. In the case of syphilis, serological tests such as VDRL and treponemal serology are essential for confirming the infection. However, it is important to note that syphilitic ulcers can be painless and, therefore, may go unnoticed during the initial clinical evaluation.

Additionally, it is crucial to consider other less common causes of genital ulcers, such as chancroid and lymphogranuloma venereum, which, although less prevalent, can coexist with more common infections and complicate the differential diagnosis. The detection of coinfections is fundamental for comprehensive patient management.

Conclusions

The accurate diagnosis of genital ulcers is vital for STD control and the prevention of long-term complications. The combination of a detailed clinical evaluation with specific laboratory tests, such as PCR for herpes simplex and serology for syphilis, is essential to differentiate between these two conditions. The implementation of diagnostic algorithms that consider the possibility of coinfections and other less common etiologies can significantly improve treatment outcomes and reduce the transmission of these infections.

Referencias

• [1] Genital Ulcers: Differential Diagnosis and Management
• [2] Diagnosis and management of genital ulcers
• [3] An Ulcer by Any Other Name: Non-herpes and Non-syphilis Ulcerative Sexually Transmitted Infections
• [4] Evaluation of a laboratory-developed multiplex real-time PCR assay for diagnosis of syphilis, herpes and chancroid genital ulcers in four public health laboratories in the USA

Created 6/1/2025