STD Questions (Clin Med 2) PDF

### **1. A 24-year-old female presents with lower abdominal pain, fever, and vaginal discharge for 4 days. On exam, cervical motion tenderness is noted. What is the most likely diagnosis?** A. Appendicitis\ B. Pelvic inflammatory disease (PID)\ C. Ovarian torsion\ D. Urinary tract infection **Answ...

### **1. A 24-year-old female presents with lower abdominal pain, fever, and vaginal discharge for 4 days. On exam, cervical motion tenderness is noted. What is the most likely diagnosis?** A. Appendicitis\ B. Pelvic inflammatory disease (PID)\ C. Ovarian torsion\ D. Urinary tract infection **Answer:** B. Pelvic inflammatory disease (PID)\ **Explanation:** Cervical motion tenderness is a hallmark sign of PID, which is often caused by ascending infections from *Neisseria gonorrhoeae* or *Chlamydia trachomatis*. Appendicitis and ovarian torsion present with more localized pain, while UTI lacks cervical motion tenderness. ### **2. A 30-year-old male reports dysuria and a purulent penile discharge. NAAT confirms *Neisseria gonorrhoeae*. What is the recommended treatment?** A. Ceftriaxone 500 mg IM in a single dose\ B. Azithromycin 1 g PO in a single dose\ C. Doxycycline 100 mg PO twice daily for 7 days\ D. Metronidazole 500 mg PO twice daily for 7 days **Answer:** A. Ceftriaxone 500 mg IM in a single dose\ **Explanation:** Gonorrhea treatment requires ceftriaxone due to widespread antibiotic resistance. Azithromycin or doxycycline is added if chlamydia co-infection has not been excluded. ### **3. A 19-year-old woman presents with yellow-green, frothy vaginal discharge and vulvar itching. A wet mount reveals motile organisms. What is the most appropriate treatment?** A. Metronidazole 500 mg PO BID for 7 days\ B. Fluconazole 150 mg PO single dose\ C. Azithromycin 1 g PO single dose\ D. Clindamycin cream intravaginally **Answer:** A. Metronidazole 500 mg PO BID for 7 days\ **Explanation:** *Trichomonas vaginalis* is treated with metronidazole. Fluconazole treats candidiasis, and azithromycin targets chlamydia. ### **4. A 32-year-old male presents with a painless ulcer on the penis and rubbery, painless lymphadenopathy. What is the next best diagnostic step?** A. Nucleic acid amplification test (NAAT)\ B. Darkfield microscopy\ C. Rapid plasma reagin (RPR)\ D. Biopsy of the ulcer **Answer:** B. Darkfield microscopy\ **Explanation:** Darkfield microscopy is used to identify *Treponema pallidum* in primary syphilis. Serologic tests like RPR are more commonly used in later stages. ### **5. A 27-year-old female with recurrent vulvovaginal candidiasis is treated with fluconazole weekly for six months. What defines recurrent infection?** A. More than 2 episodes/year\ B. More than 3 episodes/year\ C. Persistent infection for \>1 month\ D. Non-albicans species infection **Answer:** B. More than 3 episodes/year\ **Explanation:** Recurrent vulvovaginal candidiasis is defined as \>3 episodes/year, often requiring long-term maintenance therapy. ### **6. A 45-year-old man develops fever, arthralgia, and pustular rash involving the palms. He recently tested positive for gonorrhea. What is the most likely diagnosis?** A. Reactive arthritis\ B. Disseminated gonococcal infection (DGI)\ C. Secondary syphilis\ D. HIV infection **Answer:** B. Disseminated gonococcal infection (DGI)\ **Explanation:** DGI presents with fever, arthritis, and a pustular rash. Secondary syphilis involves maculopapular rashes. ### **7. A patient presents with painful grouped vesicles on the genital area. What is the gold standard diagnostic test for the suspected infection?** A. Tzanck smear\ B. PCR for HSV DNA\ C. HSV IgG serology\ D. Viral culture **Answer:** B. PCR for HSV DNA\ **Explanation:** PCR is the most sensitive and specific test for herpes simplex virus (HSV). ### **8. A 22-year-old woman presents with pelvic pain, fever, and cervical motion tenderness. What is the outpatient treatment of choice for her condition?** A. Ceftriaxone IM + Doxycycline PO\ B. Azithromycin + Metronidazole\ C. Clindamycin + Gentamicin\ D. Ciprofloxacin + Metronidazole **Answer:** A. Ceftriaxone IM + Doxycycline PO\ **Explanation:** Outpatient PID treatment includes ceftriaxone and doxycycline, often with metronidazole for anaerobic coverage. ### **9. A 16-year-old girl presents for her HPV vaccine series. What is the recommended dosing schedule if the first dose was received at age 11?** A. Two doses at 0 and 6-12 months\ B. Three doses at 0, 2, and 6 months\ C. Two doses at 0 and 1 month\ D. Three doses at 0, 1, and 12 months **Answer:** A. Two doses at 0 and 6-12 months\ **Explanation:** For adolescents under 15, a 2-dose schedule is recommended. ### **10. A patient with primary syphilis is treated with benzathine penicillin G. What side effect should they be warned about?** A. Jarisch-Herxheimer reaction\ B. Drug-induced lupus\ C. QT prolongation\ D. Anaphylaxis **Answer:** A. Jarisch-Herxheimer reaction\ **Explanation:** This febrile reaction occurs within 24 hours of initiating syphilis treatment. ### **11. A 35-year-old woman presents with foul-smelling, thin, white vaginal discharge. The pH of the vaginal fluid is \>4.5, and a whiff test is positive. What is the most likely diagnosis?** A. Trichomoniasis\ B. Bacterial vaginosis\ C. Vulvovaginal candidiasis\ D. Chlamydia **Answer:** B. Bacterial vaginosis\ **Explanation:** BV is characterized by malodorous, thin discharge with a pH \>4.5 and a positive whiff test. It is caused by an overgrowth of *Gardnerella vaginalis*. ### **12. A pregnant woman tests positive for chlamydia during her first prenatal visit. What is the most appropriate treatment?** A. Doxycycline 100 mg PO twice daily for 7 days\ B. Azithromycin 1 g PO single dose\ C. Levofloxacin 500 mg PO once daily for 7 days\ D. Metronidazole 500 mg PO twice daily for 7 days **Answer:** B. Azithromycin 1 g PO single dose\ **Explanation:** Azithromycin is safe and effective for treating chlamydia in pregnancy. Doxycycline is contraindicated during pregnancy. ### **13. A 28-year-old male presents with dysuria and clear penile discharge. NAAT testing is negative for gonorrhea and chlamydia. What is the next best step?** A. Test for *Mycoplasma genitalium\ *B. Treat empirically with azithromycin\ C. Perform a urine culture\ D. Refer to urology **Answer:** A. Test for *Mycoplasma genitalium\ ***Explanation:** Persistent or recurrent urethritis may be caused by *Mycoplasma genitalium*, a common non-gonococcal cause of urethritis. ### **14. A 29-year-old female presents with genital ulcers and tender inguinal lymphadenopathy. Darkfield microscopy confirms *Treponema pallidum*. What stage of syphilis does she have?** A. Primary syphilis\ B. Secondary syphilis\ C. Latent syphilis\ D. Tertiary syphilis **Answer:** A. Primary syphilis\ **Explanation:** The hallmark of primary syphilis is a painless genital ulcer (chancre) and regional lymphadenopathy. ### **15. A 25-year-old male presents with fever, chills, and painful unilateral scrotal swelling. What is the most likely cause?** A. Epididymitis due to *Chlamydia trachomatis\ *B. Testicular torsion\ C. Varicocele\ D. Hydrocele **Answer:** A. Epididymitis due to *Chlamydia trachomatis\ ***Explanation:** Epididymitis in men under 35 is commonly caused by STIs such as *Chlamydia trachomatis* or *Neisseria gonorrhoeae*. ### **16. A 23-year-old woman presents with diffuse, non-pruritic maculopapular rash on her palms and soles. She has fever and generalized lymphadenopathy. What is the most likely diagnosis?** A. Secondary syphilis\ B. Rocky Mountain spotted fever\ C. Viral exanthem\ D. Disseminated gonorrhea **Answer:** A. Secondary syphilis\ **Explanation:** A maculopapular rash on the palms and soles is characteristic of secondary syphilis. Generalized lymphadenopathy is another key finding. ### **17. A 30-year-old male with a history of genital herpes presents with recurrent painful vesicles. What is the best option for long-term suppression?** A. Acyclovir 400 mg PO twice daily\ B. Valacyclovir 1 g PO daily\ C. Famciclovir 250 mg PO twice daily\ D. Any of the above **Answer:** D. Any of the above\ **Explanation:** Suppressive therapy for recurrent herpes can include acyclovir, valacyclovir, or famciclovir, with similar efficacy. ### **18. A 33-year-old woman presents with painless genital warts. Which HPV types are most commonly associated with her condition?** A. HPV 6 and 11\ B. HPV 16 and 18\ C. HPV 31 and 33\ D. HPV 45 and 52 **Answer:** A. HPV 6 and 11\ **Explanation:** HPV types 6 and 11 are responsible for over 90% of genital warts. ### **19. A patient presents with pelvic pain and purulent vaginal discharge. She has no known allergies. What is the inpatient regimen for this condition?** A. Ceftriaxone, doxycycline, and metronidazole\ B. Cefotetan and doxycycline\ C. Clindamycin and gentamicin\ D. Any of the above **Answer:** D. Any of the above\ **Explanation:** All listed regimens are appropriate for inpatient treatment of PID, depending on clinical severity and patient factors. ### **20. A 40-year-old man with untreated HIV presents with a painless, beefy-red ulcerative lesion in the perineal area. What is the most likely diagnosis?** A. Granuloma inguinale\ B. Chancroid\ C. Primary syphilis\ D. Genital herpes **Answer:** A. Granuloma inguinale\ **Explanation:** Granuloma inguinale caused by *Klebsiella granulomatis* presents with painless, beefy-red ulcers. It is more common in tropical areas. ### **21. A 25-year-old male presents with dysuria and purulent penile discharge. Gram stain shows intracellular gram-negative diplococci. What is the next best step in treatment?** A. Azithromycin 1 g PO single dose\ B. Ceftriaxone 500 mg IM single dose + Doxycycline 100 mg PO BID for 7 days\ C. Ciprofloxacin 500 mg PO single dose\ D. Metronidazole 2 g PO single dose **Answer:** B. Ceftriaxone 500 mg IM single dose + Doxycycline 100 mg PO BID for 7 days\ **Explanation:** Gonorrhea (intracellular gram-negative diplococci) requires treatment with ceftriaxone, and doxycycline is added to cover potential *Chlamydia trachomatis* co-infection. ### **22. A 30-year-old female presents with malodorous vaginal discharge and vaginal itching. A wet mount shows "clue cells." What is the first-line treatment?** A. Metronidazole 500 mg PO BID for 7 days\ B. Fluconazole 150 mg PO single dose\ C. Doxycycline 100 mg PO BID for 7 days\ D. Azithromycin 1 g PO single dose **Answer:** A. Metronidazole 500 mg PO BID for 7 days\ **Explanation:** Bacterial vaginosis, caused by *Gardnerella vaginalis*, is characterized by clue cells and treated with metronidazole. ### **23. A 22-year-old female presents with diffuse yellow-green vaginal discharge and vulvar irritation. Wet mount reveals motile flagellated organisms. What is the associated complication during pregnancy?** A. Preterm labor\ B. Congenital abnormalities\ C. Stillbirth\ D. None **Answer:** A. Preterm labor\ **Explanation:** *Trichomonas vaginalis* increases the risk of preterm labor, premature rupture of membranes (PROM), and low birth weight. ### **24. A 28-year-old male presents with painful genital ulcers and tender inguinal lymphadenopathy. PCR testing confirms *Haemophilus ducreyi*. What is the treatment of choice?** A. Azithromycin 1 g PO single dose\ B. Ceftriaxone 500 mg IM single dose\ C. Doxycycline 100 mg PO BID for 7 days\ D. Metronidazole 500 mg PO BID for 7 days **Answer:** A. Azithromycin 1 g PO single dose\ **Explanation:** *Haemophilus ducreyi* causes chancroid, treated with azithromycin or ceftriaxone. ### **25. A 20-year-old woman with multiple sexual partners presents with dysuria and mucopurulent cervical discharge. Cervical motion tenderness is present. NAAT confirms *Chlamydia trachomatis*. What is the recommended follow-up?** A. Retesting in 3 months\ B. Retesting in 1 year\ C. No retesting needed if asymptomatic\ D. Retesting in 6 months **Answer:** A. Retesting in 3 months\ **Explanation:** Retesting for chlamydia at 3 months ensures eradication and prevents reinfection, especially in high-risk patients. ### **26. A 45-year-old male presents with grouped vesicles on an erythematous base on his genitalia. He reports similar episodes in the past. What is the recommended management?** A. Acyclovir 400 mg PO TID for 7-10 days\ B. Metronidazole 2 g PO single dose\ C. Azithromycin 1 g PO single dose\ D. Penicillin G IM single dose **Answer:** A. Acyclovir 400 mg PO TID for 7-10 days\ **Explanation:** Recurrent genital herpes is treated with antivirals such as acyclovir, valacyclovir, or famciclovir. ### **27. A 32-year-old woman presents for routine cervical cancer screening. She is 32 years old and has no history of abnormal results. What is the recommended screening interval?** A. Pap smear every 3 years\ B. Pap smear every year\ C. Pap smear + HPV co-test every 5 years\ D. Pap smear + HPV co-test every year **Answer:** C. Pap smear + HPV co-test every 5 years\ **Explanation:** Women aged 30-65 can have cervical cancer screening with a Pap smear and HPV co-test every 5 years. ### **28. A 38-year-old female with untreated syphilis presents with fever, malaise, and diffuse maculopapular rash on her palms and soles. What is the treatment of choice?** A. Benzathine penicillin G 2.4 million units IM once\ B. Doxycycline 100 mg PO BID for 14 days\ C. Azithromycin 1 g PO single dose\ D. Ceftriaxone 500 mg IM once **Answer:** A. Benzathine penicillin G 2.4 million units IM once\ **Explanation:** Secondary syphilis is treated with benzathine penicillin G. ### **29. A 19-year-old woman presents with diffuse pelvic pain, purulent vaginal discharge, and fever. What is the diagnostic test of choice?** A. Clinical diagnosis based on symptoms\ B. Pelvic ultrasound\ C. Laparoscopy\ D. NAAT for gonorrhea and chlamydia **Answer:** A. Clinical diagnosis based on symptoms\ **Explanation:** PID is often diagnosed clinically when presenting with pelvic pain, cervical motion tenderness, and supporting symptoms. ### **30. A 24-year-old female presents with genital warts. Which HPV types are most likely involved?** A. HPV 16 and 18\ B. HPV 6 and 11\ C. HPV 31 and 33\ D. HPV 45 and 52 **Answer:** B. HPV 6 and 11\ **Explanation:** HPV types 6 and 11 cause the majority of genital warts. ### **31. A 30-year-old woman presents with recurrent vulvovaginal candidiasis (\>3 episodes/year). Which treatment is most appropriate?** A. Weekly fluconazole 150 mg PO for 6 months\ B. Metronidazole 500 mg PO BID for 7 days\ C. Clotrimazole cream for 7 days\ D. Boric acid suppositories for 2 weeks **Answer:** A. Weekly fluconazole 150 mg PO for 6 months\ **Explanation:** Recurrent vulvovaginal candidiasis requires maintenance therapy with fluconazole. ### **32. A pregnant woman with a history of HSV presents at 37 weeks with active genital lesions. What is the recommended mode of delivery?** A. Vaginal delivery\ B. Cesarean section\ C. Induction of labor\ D. Observation **Answer:** B. Cesarean section\ **Explanation:** Cesarean delivery reduces the risk of neonatal herpes transmission in the presence of active lesions. ### **33. A 27-year-old male presents with a single painless penile ulcer and regional lymphadenopathy. RPR is non-reactive. What is the next diagnostic step?** A. Darkfield microscopy\ B. Repeat RPR in 2 weeks\ C. HSV PCR\ D. NAAT for gonorrhea and chlamydia **Answer:** A. Darkfield microscopy\ **Explanation:** In early primary syphilis, RPR may be non-reactive; darkfield microscopy can confirm *Treponema pallidum*. ### **34. A 22-year-old female presents with frothy vaginal discharge and a strawberry cervix on exam. What is the recommended partner treatment?** A. Metronidazole 2 g PO single dose\ B. Azithromycin 1 g PO single dose\ C. Doxycycline 100 mg PO BID for 7 days\ D. No partner treatment is needed **Answer:** A. Metronidazole 2 g PO single dose\ **Explanation:** Both partners must be treated for *Trichomonas vaginalis* to prevent reinfection. ### **35. A 29-year-old male presents with a painless, beefy-red ulcer on the genital area. What is the causative organism?** A. *Klebsiella granulomatis\ *B. *Haemophilus ducreyi\ *C. *Treponema pallidum\ *D. *Chlamydia trachomatis* **Answer:** A. *Klebsiella granulomatis\ ***Explanation:** Granuloma inguinale, caused by *Klebsiella granulomatis*, presents with beefy-red ulcers. ### **36. A 19-year-old female presents with a diffuse maculopapular rash, including on her palms and soles, and generalized lymphadenopathy. She admits to a painless genital sore two months ago that resolved on its own. What is the most likely diagnosis?** A. Secondary syphilis\ B. Erythema multiforme\ C. Disseminated gonorrhea\ D. HIV acute retroviral syndrome **Answer:** A. Secondary syphilis\ **Explanation:** Secondary syphilis presents with systemic symptoms, including rash on palms and soles and lymphadenopathy. The history of a painless genital sore (chancre) suggests prior primary syphilis. ### **37. A 25-year-old male presents with severe dysuria and no discharge. NAAT for gonorrhea and chlamydia is negative. What pathogen should be considered in this case?** A. *Mycoplasma genitalium\ *B. *Trichomonas vaginalis\ *C. *Haemophilus ducreyi\ *D. *Candida albicans* **Answer:** A. *Mycoplasma genitalium\ ***Explanation:** *Mycoplasma genitalium* is a common cause of non-gonococcal urethritis, particularly in cases with negative gonorrhea and chlamydia results. ### **38. A 23-year-old female presents with cervical motion tenderness, uterine tenderness, and adnexal tenderness. She is febrile with purulent cervical discharge. What is the most appropriate initial management?** A. Admit for IV antibiotics\ B. Prescribe oral ceftriaxone and doxycycline\ C. Observation with NSAIDs for pain relief\ D. Perform laparoscopy **Answer:** A. Admit for IV antibiotics\ **Explanation:** Severe pelvic inflammatory disease (PID) with systemic symptoms such as fever and purulent discharge warrants inpatient management with parenteral antibiotics. ### **39. A 28-year-old male with painful ulcers on his genitalia is found to have *Haemophilus ducreyi* on culture. What additional clinical finding is often associated with this condition?** A. Tender inguinal lymphadenopathy\ B. Painless chancre\ C. Condylomata acuminata\ D. Strawberry cervix **Answer:** A. Tender inguinal lymphadenopathy\ **Explanation:** Chancroid caused by *Haemophilus ducreyi* presents with painful genital ulcers and tender inguinal lymphadenopathy. ### **40. A 32-year-old pregnant woman tests positive for syphilis during her first prenatal visit. What is the treatment of choice?** A. Benzathine penicillin G\ B. Azithromycin\ C. Ceftriaxone\ D. Doxycycline **Answer:** A. Benzathine penicillin G\ **Explanation:** Penicillin G is the only treatment effective in preventing congenital syphilis in pregnancy. ### **41. A 24-year-old female presents with frothy vaginal discharge and a strawberry cervix on exam. She denies recent sexual activity but admits to sharing a towel with a roommate. What is the causative organism?** A. *Trichomonas vaginalis\ *B. *Gardnerella vaginalis\ *C. *Candida albicans\ *D. *Chlamydia trachomatis* **Answer:** A. *Trichomonas vaginalis\ ***Explanation:** *Trichomonas vaginalis* can be transmitted via fomites, including towels, though sexual transmission is more common. ### **42. A 27-year-old female presents with recurrent vaginal itching and thick, white, curd-like discharge. What is the first-line treatment?** A. Fluconazole 150 mg PO single dose\ B. Metronidazole 500 mg PO BID for 7 days\ C. Doxycycline 100 mg PO BID for 7 days\ D. Azithromycin 1 g PO single dose **Answer:** A. Fluconazole 150 mg PO single dose\ **Explanation:** Vulvovaginal candidiasis caused by *Candida albicans* is effectively treated with fluconazole. ### **43. A 45-year-old male presents with beefy-red ulcers on the genital area. Biopsy reveals Donovan bodies. What is the causative organism?** A. *Klebsiella granulomatis\ *B. *Haemophilus ducreyi\ *C. *Chlamydia trachomatis\ *D. *Treponema pallidum* **Answer:** A. *Klebsiella granulomatis\ ***Explanation:** Granuloma inguinale is caused by *Klebsiella granulomatis*, characterized by beefy-red ulcers and Donovan bodies on histology. ### **44. A 31-year-old male presents with fever, joint pain, and a pustular rash. What test would confirm the diagnosis of disseminated gonococcal infection?** A. NAAT from the affected site\ B. Blood cultures\ C. Synovial fluid culture\ D. All of the above **Answer:** D. All of the above\ **Explanation:** Disseminated gonococcal infection (DGI) can be diagnosed via NAAT, blood cultures, or synovial fluid culture, depending on the presentation. ### **45. A 19-year-old woman presents with cervical motion tenderness, fever, and adnexal tenderness. What are risk factors for this condition?** A. Multiple sexual partners\ B. Recent intrauterine device (IUD) placement\ C. Previous PID\ D. All of the above **Answer:** D. All of the above\ **Explanation:** Risk factors for PID include multiple partners, recent IUD placement, and a history of PID. ### **46. A 30-year-old male presents with painless genital warts. What is the primary goal of treatment?** A. Reduce infectivity\ B. Remove visible warts for symptom relief\ C. Prevent HPV-related cancers\ D. Eradicate HPV infection **Answer:** B. Remove visible warts for symptom relief\ **Explanation:** Treatment of genital warts focuses on removing visible lesions to relieve symptoms. HPV itself cannot be eradicated. ### **47. A 40-year-old woman presents with recurrent genital herpes outbreaks. Which antiviral regimen is recommended for suppressive therapy?** A. Valacyclovir 1 g PO daily\ B. Acyclovir 200 mg PO 5 times daily\ C. Famciclovir 250 mg PO BID\ D. All of the above **Answer:** D. All of the above\ **Explanation:** Suppressive regimens for recurrent herpes include valacyclovir, acyclovir, or famciclovir. ### **48. A 36-year-old male presents with genital ulcers and tender, rubbery inguinal lymphadenopathy. Serologic testing for syphilis is reactive. What is the causative organism?** A. *Treponema pallidum\ *B. *Haemophilus ducreyi\ *C. *Chlamydia trachomatis\ *D. *Klebsiella granulomatis* **Answer:** A. *Treponema pallidum\ ***Explanation:** Syphilis, caused by *Treponema pallidum*, presents with ulcers and rubbery lymphadenopathy. ### **49. A pregnant woman is diagnosed with *Trichomonas vaginalis*. What is the treatment of choice?** A. Metronidazole 2 g PO single dose\ B. Metronidazole 500 mg PO BID for 7 days\ C. Tinidazole 2 g PO single dose\ D. Fluconazole 150 mg PO single dose **Answer:** A. Metronidazole 2 g PO single dose\ **Explanation:** Metronidazole is safe in pregnancy and effective against *Trichomonas vaginalis*. ### **50. A patient is diagnosed with primary syphilis. What is the typical timeframe for the chancre to heal without treatment?** A. 1-2 weeks\ B. 3-6 weeks\ C. 6-12 weeks\ D. 12-16 weeks **Answer:** B. 3-6 weeks\ **Explanation:** The chancre of primary syphilis heals spontaneously within 3-6 weeks without treatment. ### **51. Which sexually transmitted infection (STI) has the highest rate of congenital transmission if left untreated during pregnancy?** A. Gonorrhea\ B. Chlamydia\ C. Syphilis\ D. Trichomoniasis **Answer:** C. Syphilis\ **Explanation:** Untreated syphilis during pregnancy can result in congenital syphilis in up to 80% of cases, leading to significant morbidity and mortality. ### **52. What diagnostic test is the gold standard for confirming *Candida albicans* infection?** A. Wet mount microscopy\ B. Gram stain\ C. Culture\ D. PCR testing **Answer:** C. Culture\ **Explanation:** While microscopy and KOH tests are helpful, culture is the gold standard for diagnosing *Candida albicans*. ### **53. What symptom is most commonly associated with vulvovaginal candidiasis?** A. Vaginal soreness\ B. Frothy yellow-green discharge\ C. Foul fishy odor\ D. Genital ulcers **Answer:** A. Vaginal soreness\ **Explanation:** Vulvovaginal candidiasis typically causes pruritus, soreness, and thick, white discharge. ### **54. What is the causative organism of chancroid?** A. *Treponema pallidum\ *B. *Haemophilus ducreyi\ *C. *Klebsiella granulomatis\ *D. *Chlamydia trachomatis* **Answer:** B. *Haemophilus ducreyi\ ***Explanation:** Chancroid is caused by *Haemophilus ducreyi* and presents with painful ulcers and inguinal lymphadenopathy. ### **55. What is the recommended treatment for uncomplicated gonococcal infections?** A. Ceftriaxone 500 mg IM single dose\ B. Azithromycin 1 g PO single dose\ C. Ciprofloxacin 500 mg PO single dose\ D. Doxycycline 100 mg PO BID for 7 days **Answer:** A. Ceftriaxone 500 mg IM single dose\ **Explanation:** Ceftriaxone is the first-line treatment for gonorrhea due to antibiotic resistance in other drugs. ### **56. What is a characteristic feature of primary syphilis?** A. Non-pruritic rash on palms and soles\ B. Painless chancre at the site of inoculation\ C. Condylomata lata\ D. Generalized lymphadenopathy **Answer:** B. Painless chancre at the site of inoculation\ **Explanation:** A painless chancre is the hallmark of primary syphilis. ### **57. What is the most common non-viral sexually transmitted infection in the United States?** A. Trichomoniasis\ B. Gonorrhea\ C. Chlamydia\ D. Syphilis **Answer:** A. Trichomoniasis\ **Explanation:** *Trichomonas vaginalis* is the most prevalent non-viral STI in the U.S. ### **58. What laboratory finding is diagnostic for bacterial vaginosis?** A. Pseudohyphae on wet mount\ B. Motile trichomonads on microscopy\ C. Clue cells on wet mount\ D. Gram-negative diplococci **Answer:** C. Clue cells on wet mount\ **Explanation:** Clue cells are epithelial cells covered with bacteria, characteristic of bacterial vaginosis. ### **59. Which STI is associated with a \"strawberry cervix\"?** A. Trichomoniasis\ B. Chlamydia\ C. Syphilis\ D. HPV **Answer:** A. Trichomoniasis\ **Explanation:** The \"strawberry cervix\" appearance is caused by *Trichomonas vaginalis* infection. ### **60. What is the primary treatment for bacterial vaginosis?** A. Metronidazole 500 mg PO BID for 7 days\ B. Fluconazole 150 mg PO single dose\ C. Azithromycin 1 g PO single dose\ D. Doxycycline 100 mg PO BID for 7 days **Answer:** A. Metronidazole 500 mg PO BID for 7 days\ **Explanation:** Metronidazole is the first-line treatment for bacterial vaginosis. ### **61. A 30-year-old male presents with genital ulcers and lymphadenopathy. Darkfield microscopy is positive. What is the likely causative organism?** A. *Treponema pallidum\ *B. *Haemophilus ducreyi\ *C. *Chlamydia trachomatis\ *D. *Klebsiella granulomatis* **Answer:** A. *Treponema pallidum\ ***Explanation:** Positive darkfield microscopy indicates syphilis caused by *Treponema pallidum*. ### **62. Which HPV types are most associated with cervical cancer?** A. 6 and 11\ B. 16 and 18\ C. 31 and 33\ D. 45 and 52 **Answer:** B. 16 and 18\ **Explanation:** HPV types 16 and 18 are responsible for the majority of cervical cancers. ### **63. What is the most common complication of untreated pelvic inflammatory disease (PID)?** A. Tubo-ovarian abscess\ B. Infertility\ C. Ectopic pregnancy\ D. Chronic pelvic pain **Answer:** B. Infertility\ **Explanation:** Infertility is the most common long-term complication of untreated PID due to tubal damage. ### **64. What is the recommended treatment for recurrent vulvovaginal candidiasis?** A. Fluconazole weekly for 6 months\ B. Metronidazole 500 mg PO BID for 7 days\ C. Boric acid suppositories for 2 weeks\ D. Clotrimazole cream for 7 days **Answer:** A. Fluconazole weekly for 6 months\ **Explanation:** Recurrent vulvovaginal candidiasis requires maintenance therapy with weekly fluconazole. ### **65. What is the most sensitive test for detecting *Trichomonas vaginalis*?** A. Wet mount microscopy\ B. NAAT (PCR)\ C. Culture\ D. Antigen testing **Answer:** B. NAAT (PCR)\ **Explanation:** NAAT is the most sensitive test for *Trichomonas vaginalis* detection. ### **66. What is the next best step for a pregnant woman with an abnormal Pap smear showing ASC-US?** A. HPV testing\ B. Repeat Pap smear in 6 months\ C. Colposcopy\ D. Biopsy **Answer:** A. HPV testing\ **Explanation:** Reflex HPV testing helps determine the need for further evaluation in ASC-US cases. ### **67. What organism causes granuloma inguinale?** A. *Klebsiella granulomatis\ *B. *Haemophilus ducreyi\ *C. *Treponema pallidum\ *D. *Chlamydia trachomatis* **Answer:** A. *Klebsiella granulomatis\ ***Explanation:** *Klebsiella granulomatis* causes granuloma inguinale, presenting as beefy-red ulcers. ### **68. What is the mechanism of action for metronidazole in treating STIs?** A. Inhibits bacterial cell wall synthesis\ B. Disrupts bacterial DNA synthesis\ C. Inhibits protein synthesis\ D. Alters bacterial membrane permeability **Answer:** B. Disrupts bacterial DNA synthesis\ **Explanation:** Metronidazole disrupts bacterial DNA synthesis, making it effective against anaerobic bacteria and protozoa. ### **69. What is a common adverse effect of the Jarisch-Herxheimer reaction in syphilis treatment?** A. Fever and myalgia\ B. QT prolongation\ C. Gastrointestinal distress\ D. Rash **Answer:** A. Fever and myalgia\ **Explanation:** The Jarisch-Herxheimer reaction is an acute febrile reaction occurring within 24 hours of initiating syphilis treatment. ### **70. What is the diagnostic test of choice for confirming HSV in vesicular lesions?** A. Tzanck smear\ B. Viral culture\ C. PCR testing\ D. HSV IgG serology **Answer:** C. PCR testing\ **Explanation:** PCR testing is the most sensitive and specific test for confirming HSV. ### **71. What is the recommended treatment for a pregnant woman with *Trichomonas vaginalis* infection?** A. Metronidazole 2 g PO single dose\ B. Tinidazole 2 g PO single dose\ C. Metronidazole 500 mg PO BID for 7 days\ D. No treatment recommended in pregnancy **Answer:** A. Metronidazole 2 g PO single dose\ **Explanation:** Metronidazole 2 g PO single dose is safe and effective for treating *Trichomonas vaginalis* in pregnant women. ### **72. What are clue cells, and in which condition are they seen?** A. Vaginal epithelial cells coated with bacteria; bacterial vaginosis\ B. Vaginal epithelial cells with pseudohyphae; candidiasis\ C. Vaginal epithelial cells with motile organisms; trichomoniasis\ D. Vaginal epithelial cells with intracellular diplococci; gonorrhea **Answer:** A. Vaginal epithelial cells coated with bacteria; bacterial vaginosis\ **Explanation:** Clue cells are epithelial cells covered with adherent bacteria, seen in bacterial vaginosis. ### **73. What clinical finding differentiates chancroid from primary syphilis?** A. Tender inguinal lymphadenopathy\ B. Painful genital ulcers\ C. Non-tender genital ulcers\ D. Rash on palms and soles **Answer:** B. Painful genital ulcers\ **Explanation:** Chancroid caused by *Haemophilus ducreyi* presents with painful ulcers, whereas syphilitic chancres are painless. ### **74. What is the hallmark clinical finding of disseminated gonococcal infection (DGI)?** A. Painless genital ulcers\ B. Tenosynovitis, arthritis, and skin lesions\ C. Strawberry cervix\ D. Fever and non-pruritic rash on palms **Answer:** B. Tenosynovitis, arthritis, and skin lesions\ **Explanation:** DGI is characterized by systemic symptoms, including joint inflammation and pustular or vesiculopustular skin lesions. ### **75. What diagnostic test is most sensitive for diagnosing *Chlamydia trachomatis* infections?** A. Gram stain\ B. Culture\ C. NAAT (nucleic acid amplification test)\ D. Direct fluorescent antibody test **Answer:** C. NAAT (nucleic acid amplification test)\ **Explanation:** NAAT is the gold standard for diagnosing *Chlamydia trachomatis* due to its high sensitivity and specificity. ### **76. Which STI is most likely associated with neonatal conjunctivitis occurring 5-12 days after birth?** A. Gonorrhea\ B. Chlamydia\ C. Syphilis\ D. Herpes simplex virus **Answer:** B. Chlamydia\ **Explanation:** Neonatal conjunctivitis from *Chlamydia trachomatis* typically develops 5-12 days postpartum. ### **77. What is the primary purpose of HPV vaccination?** A. Eradicate HPV infections\ B. Reduce the prevalence of genital warts\ C. Prevent cervical cancer and other HPV-related cancers\ D. Prevent all sexually transmitted infections **Answer:** C. Prevent cervical cancer and other HPV-related cancers\ **Explanation:** HPV vaccination is most effective in preventing cancers caused by high-risk HPV types 16 and 18. ### **78. A 24-year-old man presents with painful grouped vesicles on the penile shaft. What is the most appropriate diagnostic test?** A. PCR for HSV DNA\ B. Wet mount microscopy\ C. RPR test\ D. Gram stain **Answer:** A. PCR for HSV DNA\ **Explanation:** PCR is the most sensitive and specific test for herpes simplex virus. ### **79. A 34-year-old woman presents with recurrent episodes of vulvar pain, vesicles, and ulceration. She is concerned about transmission to her partner. What is the best long-term management option?** A. Acyclovir 400 mg PO BID daily for suppression\ B. Acyclovir 400 mg PO TID during episodes only\ C. Metronidazole 500 mg PO BID for suppression\ D. No suppression; education only **Answer:** A. Acyclovir 400 mg PO BID daily for suppression\ **Explanation:** Daily suppressive therapy reduces the frequency of herpes recurrences and transmission risk. ### **80. What are the initial management steps for a patient with suspected pelvic inflammatory disease (PID) and an IUD in place?** A. Remove the IUD and start antibiotics\ B. Leave the IUD in place and start antibiotics\ C. Remove the IUD, start antibiotics, and recommend hospitalization\ D. Recommend surgical removal of the IUD **Answer:** B. Leave the IUD in place and start antibiotics\ **Explanation:** Current guidelines recommend leaving the IUD in place during antibiotic treatment for PID unless symptoms persist or worsen. ### **81. What diagnostic test confirms the diagnosis of granuloma inguinale?** A. Visualization of Donovan bodies on biopsy\ B. NAAT for *Klebsiella granulomatis\ *C. Darkfield microscopy\ D. Gram stain of ulcer exudate **Answer:** A. Visualization of Donovan bodies on biopsy\ **Explanation:** Granuloma inguinale caused by *Klebsiella granulomatis* is confirmed by the presence of Donovan bodies on biopsy. ### **82. A 27-year-old woman presents with mucopurulent cervical discharge and cervical motion tenderness. What is the outpatient treatment for this condition?** A. Ceftriaxone + Doxycycline + Metronidazole\ B. Azithromycin + Metronidazole\ C. Doxycycline + Ciprofloxacin\ D. Ceftriaxone only **Answer:** A. Ceftriaxone + Doxycycline + Metronidazole\ **Explanation:** This combination covers *N. gonorrhoeae*, *C. trachomatis*, and anaerobes in pelvic inflammatory disease. ### **83. Which of the following is true about the HPV vaccine schedule?** A. Two doses are recommended for those vaccinated before age 15\ B. Three doses are required for everyone, regardless of age\ C. The vaccine only protects against cervical cancer\ D. The vaccine is ineffective if given after age 21 **Answer:** A. Two doses are recommended for those vaccinated before age 15\ **Explanation:** A 2-dose schedule is recommended for adolescents initiating the vaccine before age 15. ### **84. What is the main feature that distinguishes bacterial vaginosis from other causes of vaginal discharge?** A. Vaginal pH \>4.5\ B. Strawberry cervix\ C. Thick, white, curd-like discharge\ D. Painful ulcers **Answer:** A. Vaginal pH \>4.5\ **Explanation:** BV is characterized by pH \>4.5 and malodorous discharge without significant inflammation. ### **85. What is the first-line treatment for syphilis during pregnancy?** A. Benzathine penicillin G IM\ B. Azithromycin PO\ C. Doxycycline PO\ D. Ceftriaxone IM **Answer:** A. Benzathine penicillin G IM\ **Explanation:** Penicillin is the only treatment effective in preventing congenital syphilis. ### **86. What finding is most consistent with recurrent genital herpes?** A. Painless genital ulcers\ B. Painful vesicles on an erythematous base\ C. Painful inguinal lymphadenopathy only\ D. Frothy vaginal discharge **Answer:** B. Painful vesicles on an erythematous base\ **Explanation:** Recurrent genital herpes presents as painful vesicles or ulcers on an erythematous base. ### **87. What STI is associated with a frothy, malodorous discharge and increased risk of HIV acquisition?** A. Trichomoniasis\ B. Bacterial vaginosis\ C. Gonorrhea\ D. Syphilis **Answer:** A. Trichomoniasis\ **Explanation:** *Trichomonas vaginalis* is associated with frothy, malodorous discharge and increased susceptibility to HIV. ### **88. What is the management for cervical intraepithelial neoplasia (CIN) 2 confirmed by colposcopy?** A. Observation in women \4.5. What is the treatment of choice?** A. Metronidazole 500 mg PO BID for 7 days\ B. Fluconazole 150 mg PO single dose\ C. Azithromycin 1 g PO single dose\ D. Ceftriaxone 500 mg IM single dose **Answer:** A. Metronidazole 500 mg PO BID for 7 days\ **Explanation:** Bacterial vaginosis is characterized by clue cells and treated with metronidazole. ### **96. What is the most common complication associated with untreated chlamydial infection in women?** A. Infertility\ B. Cervical cancer\ C. Genital warts\ D. Herpes simplex virus reactivation **Answer:** A. Infertility\ **Explanation:** Untreated chlamydial infection can lead to pelvic inflammatory disease and subsequent infertility. ### **97. A 31-year-old woman presents with painful genital ulcers and tender inguinal lymphadenopathy. PCR confirms *Haemophilus ducreyi*. What is the treatment of choice?** A. Azithromycin 1 g PO single dose\ B. Ceftriaxone 500 mg IM single dose\ C. Metronidazole 500 mg PO BID for 7 days\ D. Doxycycline 100 mg PO BID for 7 days **Answer:** A. Azithromycin 1 g PO single dose\ **Explanation:** Chancroid caused by *Haemophilus ducreyi* is treated with azithromycin or ceftriaxone. ### **98. A 22-year-old male presents with a single painless ulcer on the penis. Serology is negative for syphilis. What is the next diagnostic step?** A. Darkfield microscopy\ B. PCR for HSV DNA\ C. RPR repeat in 2 weeks\ D. NAAT for gonorrhea **Answer:** A. Darkfield microscopy\ **Explanation:** Darkfield microscopy can identify *Treponema pallidum* in early primary syphilis when serology is negative. ### **99. A 45-year-old female presents with frothy yellow-green vaginal discharge and vulvar itching. She denies sexual activity. Which form of transmission should be considered?** A. Fomite transmission\ B. Hematogenous spread\ C. Vertical transmission\ D. Respiratory droplet transmission **Answer:** A. Fomite transmission\ **Explanation:** *Trichomonas vaginalis* can occasionally be transmitted through fomites, though sexual transmission is more common. ### **100. A 32-year-old female with recurrent genital herpes is concerned about transmission to her partner. What advice should you provide?** A. Daily antiviral therapy reduces transmission risk\ B. Use of condoms completely prevents transmission\ C. HSV IgG testing of her partner is unnecessary\ D. Avoid sexual activity only during symptomatic outbreaks **Answer:** A. Daily antiviral therapy reduces transmission risk\ **Explanation:** Daily suppressive antiviral therapy reduces HSV shedding and transmission risk. ### **1. Epidemiology of STIs** - - - - - - ### **2. STI Prevention** - - - - ### **3. Common Presentations and Associated STIs** - - - - - - - - - - - - ### **4. Diagnostic Tools** - - - - - - - - - - ### **5. Treatment Guidelines** - - - - - - - - - - - - - - ### **6. Complications** - - - - - - - - - - - - ### **7. Special Populations** - - - - - - - ### **8. High-Yield Visual Clues** - - - - ### **9. Follow-Up and Prevention** - - - - - - ### **10. Special Conditions** - - - - - ### **Exam Tip:** Focus on: - - -