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NBME 21 Answers

nbme21/Block 1/Question#39 (reveal difficulty score)
A 33-year-old woman comes to the physician ...
Genital herpes ๐Ÿ” / ๐Ÿ“บ / ๐ŸŒณ / ๐Ÿ“–

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 +35  upvote downvote
submitted by โˆ—madojo(212)
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Know your STD's baby ;-) (going through every other choice on this question):

  • Bacterial vaginosis caused by gardnerella vaginallis. Se a thin, off white discharge and fishy smell (fish in the garden). There's no inflammation Lab findings: pH greater than 4.5 (just like trichomoniasis), and a positive whiff test with KOH. Stem will say something about malodorous discharge and show the infamous CLUE CELLS if we are lucky. Not the answer for this question obviously because we would not expect vesicles with this bacterial disease.

  • Candidiasis is going to be your thick cottage cheese discharge, with inflammation. normal pH see pseudohyphae. Treat with topical nystatin, or oral fluconazole unless you're pregnant than use Clotrimazole. Again not going to see any vesicles.

  • Chancroid per uworld is associated with Haemophilus ducreyi you will have a Deep purulent painful ulcer with suppurative lymphadenitis. Will be told that patient has painful inguinal nodes, there may be multiple deep ulcers with gray-yellow exudate. You do cry with H. duCRYi This wouldn't be true for what our patient has in this question because we aren't told of any inguinal adenopathy. a link to a chancroid VDA

  • Chlamydia trachomatis causes lymphogranuloma venereum which is small shallow ulcers, painless, but then the large painful coalesced inguinal lymph nodes aka BUBOES. Compared with gonnorhea the discharge is more thinner and watery. Again not the case here as its painful and no mention of any BUBOOESS. The discharge in gonorrhea is more thicker. Both lead to PID, treat for both because confection is common. With both patient may have some sort of pain or burning sensation upon urination. Sterile pyuria though for both.

  • Condyloma accuminatum is a manifestation of HPV 6 + 11 (genital warts). They look like big cauliflowers. This is in contrast to Condyloma lata that you see in syphillis which is just a flatter latte brown looking macule.

  • Genital Herpes (the answer to the question) will present with multiple painful superficial vesicles or ulcerations with constitutional symptoms (fever, malaise) Just fits better than all the other choices I ran through.

  • Syphillis is the painless chancre. UW describes it as a single, indurated well circumscribed ulcer, with a clean base. See corkscrew organisms on DF microscopy. Keep in mind other painless ulcers are lymphogranuloma venereum of clamydia (but the buboes are whats painful not the ulcer), and granuloma inguinale (donovanosis - klebsiella granulomatis) but whats hallmark about this one is that its painless without lymphadenopathy

In short, be safe.

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drdoom  this write-up is AWESOME ... but it also made me vomit. +1
b1ackcoffee  This is awesome, writeup, not the stds. +1
lovebug  FA 2019 pg 184. I summed up @madojo's comment! this patient have "multiple, tender vesicles and ulcer". and scant vaginal discharge. A) Bacterial vaginosis -> NO vesicle -> r/o B) Candidiasis -> NO vesicle -> r/o C) Chancroid -> should have Inguinal Adenopathy -> r/o D) C. trachomatis -> have Large painful inguinal LN -> r/o E) Condyloma acuminata -> Big Cauliflower -> r/o F) Gental herpes -> YES!!! G) Gonorrhea -> NO Vesicle, creamy prulent discharge -> r/o H) C. trachomatis again (same as D) -> r/o I) Syphilis -> painless chancre -> r/o J) Trichomoniasis -> strawberry cervix, motile in wet prep -> r/o thanks @madojo! +
homersimpson  Gotta love the BUBOES +

 +3  upvote downvote
submitted by gabstep(15)
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FA 2019 pg184: Genital herpes presents with painful vulvar or cervical vesicles and ulcers; can cause systemic symptoms such as fever, headache, myalgia

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sam.l  the question stem states a "a scent vaginal discharge" is that a distractor in the question. +
kentuckyfan  "Scant" means very little. +1

 +2  upvote downvote
submitted by โˆ—tissue creep(133)
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If anybody has a good way of distinguishing/remembering all the different presentations for genital sores, I'd appreciate the help.

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hungrybox  Pls post as a separate post and not a comment to this tho. The formatting for these comments sux +1
whossayin  Assuming u have UWorld, just type sexually transmitted infections.. that table is the best IMO +
lumd  Thank you so much for the tip! Didn't know that you can search for specific topics in UW. +

 +0  upvote downvote
submitted by โˆ—yotsubato(1208)
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Why is this NOT chancroid? Theres nothing here that rules it out.

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drachenx  Chancroid is described as an ulcer.. whilst in this question they mentioned "vesicles". Pretty much only herpes is vesicular +6
whoissaad  They mentioned ulcers too. I chose chancroid as well, couldn't find a clue to rule it out. Also thought "discharge" was pointing you towards a bacterial infection. But guess I'm wrong :) +
emmy2k21  I think NBME/USMLE writers make the assumption the patient is in America unless specified otherwise. Chancroid is not common in the US. If the question stem mentions a developing country, then chancroid can make your differential list. +1
selectuw  for chancroid, there may be a mention of inguinal lymphadenopathy +2
samsam3711  Also with chancroid questions they want you to differentiate it between chancroid and syphilis, (eg. Painful vs. painless) and is usually described as a much larger ulcer that is painful (not vesicular as in this question) +
suckitnbme  Also believe that chancroid does not presents with systemic symptoms like in this vignette. +

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