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Kaplan Qbank USMLE



Author15 Posts
  #1

A 30-year-old woman who is menstruating develops tenderness of the right knee. She has had arthralgias involving her wrists and knees for the past 3 days. She has no urinary tract symptoms or vaginal discharge. The right knee is swollen and warm to the touch. Approximately 10 necrotic pustules are present on her upper and lower extremities. A Gram stain of scrapings from the cervical os is shown. Which of the following is the most likely causal organism?


A. Calymmatobacterium donovani
B. Chlamydia trachomatis
C. Haemophilus ducreyi
D. Neisseria gonorrhoeae
E. Neisseria meningitidis

shocked

  #2

D

  #3

D

___________________
The Key to Succeed is Patience.

  #4

Gonorrhea causes necrotic pustules?! Shouldn't the patient have a vaginal discharge as well!?

shocked

  #5

in females gonorrhea infection is largely asymptomatic thus females serve as good carriers for the disease....so a vaginal discharge is not essential...

  #6

agree with D

  #7

D, THE OLIGOARTHRALGIA GIVES IT OUT.

___________________
footsteps on the sands of time are not made by sitting around.

  #8

nodi agree




  #9

in original question, there is a picture. I think that picture is Chlamydia's.

Chlamydia trachomatis can cause reactive arthritis.



  #10

well...no picture here, but does chlamydia cause pustules? and can you see chlamydia on gram stain? I still go with D

___________________
fight possessed

  #11

from what I know none of those abov produce pustules

does chlamidia produce arthralgias? I know about reiter's sdr, but that is suppose to happen to men and also be asociated w/ conjunctivitis. so, the only logical answer would be Gonococcal arthritis

i'd like to see the picture, though

___________________
"Love is the only inflamation of the heart that drains in the vagina" (translation after Dr Petre Florescu, Professor of Pathology, UMF "Iuliu Hatieganu", Cluj Napoca

  #12

good point about the gram stain vallia

___________________
"Love is the only inflamation of the heart that drains in the vagina" (translation after Dr Petre Florescu, Professor of Pathology, UMF "Iuliu Hatieganu", Cluj Napoca

  #13

The clue is menstruation- because she was menstruating was easier for the N.gon. to achieve the blood stream and to give disseminated gonococemia. The most common forms of disseminated infection are a dermatitis-arthritis syndrome, endocarditis and meningitis.


  #14

I came across this thread, and I had to revive it. There appears to a be confusion of what chlamydia and gonorrhea looks like.

N. Gonorrhea has diplococci



C. Trachomatis looks like...




  #15

For the record, you cannot see Chlamydia on gram stains. In the "olden" days we used to see lots of gram smears like the first one (positive for GC) and the second one (used to be termed "nonspecific urethritis"). None of the organisms on the second smear are Chlamydia.

Last night we received a gram stain and culture on a male with urethral discharge. What makes this remarkable is that NOBODY in our hospital system orders cultures on these any more. A Chlamydia/gonorrhoeae DNA amplification test is ordered on either a urine or urethral swab for men, or a urine or vaginal swab for women. It made me wonder how old the doc was who ordered it......some of our older docs just don't want to embrace new methodology [sigh]....

A gram stain on a MALE like the first one above is diagnostic for GC. If one sees gram negative diplococci in a female it is NOT diagnostic. It can be highly suggestive of GC but, because of normal vaginal flora, is not diagnostic.

We set up a Thayer Martin selective agar for GC on all knee fluid/joint fluid specimens. We get a positive blood culture for GC every couple of years. I remember going down to the ER years ago and drawing blood cultures on a female patient who was running a temp but didn't seem particularly ill, as she was chatting to me and her friend. Two days later her BC's turned positive for GC. I was quite surprised.

I used to sell testing for Chlamydia when it first came out. We always told the doc to clear the cervical OS of mucus and purulent material, as Chlamydia lived in the columnar epis inside the OS of the cervix. I believe many Chlamydia kits provide a large swab for this very purpose so that then the doc can collect for Chlamydia with the collection device. (You guys ARE doing that, aren't you?????). Chlamydia do not live inside WBC's. Pus doesn't cut it for a Chlamydia specimen. You need to get to the columnar epis. In a man, this is inside the penis (ouch). The collection kit for the male comes with a small tipped wire swab just for this purpose. With the new Uriprobe testing, urine specimens are less painful and easy to obtain, and they work if the lab has validated urine testing for their kits (we have).

Chlamydia are difficult to culture for. DNA amplification is very sensitive.

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Clinical Microbiology since 1974







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