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

A 52-year-old male patient presented to our clinic with complaints of a painful genital ulcer and inguinal lymphadenopathy. Serologic tests for syphilis revealed elevated Treponema pallidum latex agglutination (TPLA) and rapid plasma regain (RPR) levels, leading to a diagnosis of primary syphilis. He was treated with a single intramuscular dose of 2.4 million units of benzathine penicillin G; however, there was no improvement in the genital ulcer. The patient, a seafarer on an international cargo ship, was diagnosed with chancroid after his Filipino roommate was confirmed to have the disease. His genital ulcer resolved after a single oral dose of 1 g of azithromycin. Subsequent testing showed a decrease in serum TPLA and RPR levels. Mixed infection with chancroid and syphilitic chancre is rare and should be recognized as a potential imported infectious disease.