日本性感染症学会誌 Journal of Japanese Society for Sexually Transmitted Infections

The differential diagnosis of genital ulcers can be challenging. We reported the case of a man in his 40s who presented with genital sores. Two months before his first visit, the patient had engaged in unprotected oral sex at a brothel. Over the course of the next year or so, the patient experienced three episodes of genital ulcers. The first and second episodes were diagnosed as primary syphilis based on syphilis antibody testing. The third episode was diagnosed as genital herpes based on positive HSV antigen testing. This case highlights the importance of a comprehensive diagnosis—including patient history, physical examination, and test results—in the evaluation of genital ulcers to ensure appropriate treatment selection.