Primary genital lymphogranuloma venereum in the HIV pre-exposure prophylaxis era Editor Lymphogranuloma venereum (LGV) is a sexually transmitted infection (STI) caused by Chlamydia trachomatis (CT) serovars L1-L3. 1 In Europe, it is endemic among men who have sex with men (MSM) causing proctitis, mainly co-infected with HIV, since 2003. 2 Its presentation as a genital lesion has been rarely described and accounts for around 5% of cases in the United Kingdom and France. 3,4 Increasing STIs rates in MSM have been reported during the last decade in several Western countries, 5 and it is plausible that HIV pre-exposure prophylaxis (PrEP) might contribute to maintaining this trend. 6 We report 2 cases with genital primary LGV mimicking primary syphilis seen at in our clinic in Barcelona. Case 1. A 43-year-old HIV-negative man on PrEP presented with a one-week history of a painful penile ulcer. He reported unprotected anal sex with three men in previous month. Clinically, there was a red ulcer on the dorsal side of the penis with an inguinal adenopathy on the left groin (Fig. 1). Because of a negative dark-field examination and the large size of the adenopathy, we initiated empirical treatment with doxycycline 100 mg orally twice daily. Swabs from the penile ulcer were collected for bacterial culture and multiplex PCR testing. Only CT was detected. The patient was instructed to continue up to 3 weeks of treatment. Three weeks after treatment, the penile ulcer and the inguinal mass almost disappeared.