<prompt> A 20-year-old young female presented with a relatively painless ulcer of 3 cm on the labia majora with raised margins. Which of the following organisms would have most likely caused this ulcer?Herpes simplexTreponema palladiumChlamydia trachomatisCandidal cervicitis  <response>: Ans. b. Treponema palladium Ref: Rooks 7e p17.37-17, 39.58-39.59In a female with 3x4 cm painless ulcer with raised margin on labia majora is suggestive of syphilis, caused by Treponema pallidum.Sexually Transmitted DiseasesDonovanosisSyphilisLGVChancroid Painless indurated and bleeding ulcerQ Mostly involving genitalia 90 No lymphadenopathy pseudobuboQ May lead to pseudoelephantiasis of labiaQ Caused by calymmobacterium granulomatosis Diagnosis made by microscopy by demonstration of Donovan bodiesQ or safety pin appearanceQ within large mononuclear cells in smears or biopsy sample DOC is doxy tetracyclineQ DOC in pregnancy is Azithromycin erythromycinQ Painless indurated, non bleeding usually single punched out ulcerQ Lymph nodes are rubbery Caused by Treponema pallidumQ Diagnosed by dark field microscopy, FTA-ABS most sensitive test, earliest test to become positiveQ VDRL or RPR titer determine response to treatment as they become negativeQ TPI most specific testQ TPH 2nd most sensitive test Penicillin G is drug of choiceQ for all stages of syphilis Lymph nodes are matted buboQ may suppurate and are painfulQ Asymptomatic, single, painless mostly and non-bleeding macule ulcerQ Caused by Chlamydia trachomatis - L1L2 MCQ, L3 strains Diagnosis by microscopic examination of Giemsa stained cell scrapings for inclusionelementary bodiesQ Esthiomine vaginal and rectal stricture elephantiasis of vulvaQ Freis test is done for diagnosisQ Groove sign is seenQ DOC is doxy tetracyclineQ Lymph nodes are fluctuant and spontaneously rupture and suppurateQ Ulcers develop within 7 daysQ, are multiple, painful, non indurated and bleeding soft chancreQ Caused by Hemophilus ducreyiQ Diagnosis by gram staining gram negative cocco-bacilli, school of fish and rail road appearanceQ and culture of organism DOC is Ceftriaxone. Azithromycin erythromycin. 