Snapshot A 25-year-old man presents to the urgent care center for a new lesion on his genitals. He reports that he recently went to a bachelor party in Las Vegas, where he engaged in sexual intercourse with multiple female partners. He reports only sometimes using protection. In the past week, he reports having fevers and chills along with a few painful lesions on his penis. On physical exam, there are multiple clear vesicles on his penis. He is tested for the appropriate sexually transmitted diseases and prescribed acyclovir. (Genital herpes) Introduction Introduction ulcerative genital lesions chancroid genital herpes granuloma inguinale lymphogranuloma venereum syphilis transmission sexually, often through a break in the skin risk factors multiple sexual partners unprotected sexual intercourse Chancroid Introduction organism Haemophilus ducreyi gram-negative, facultative anaerobic coccobacillus Presentation painful ulcer with exudate yellow-grey base with irregular borders may bleed when touched unilateral tender inguinal lymphadenopathy no systemic symptoms Studies Gram stain gram-negative coccobacilli culture on Nairobi medium or Mueller-Hinton agar detection of DNA with polymerase chain reaction (PCR) Treatment ceftriaxone azithromycin Genital Herpes Introduction organism herpes simplex virus 2 herpes simplex virus 1 (less common) enveloped linear double-stranded DNA virus pathogenesis latent in sacral ganglia Presentation painful clear vesicles may have ulcers if the roofs of vesicles fall off systemic symptoms fevers headaches myalgias Studies Tzanck prep multinucleated giant cells detection of DNA with PCR Treatment acyclovir, valacyclovir, or famciclovir foscarnet resistance to acyclovir Granuloma inguinale (Donovanosis) Introduction organism Klebsiella (Calymmatobacterium) granulomatis gram-negative, oxidase-negative bacillus demographics not common in the US risk factors Presentation beefy red ulcer that bleeds when touched irregular borders Studies bipolar staining Donovan bodies in cytoplasm mucoid colonies on MacConkey agar Treatment doxycycline trimethoprim-sulfamethoxazole azithromycin