Ep 137: A 21-Year-Old with Vaginal Discharge

This episode reviews the differential diagnosis and diagnostic criteria for common conditions that would cause vaginal discharge.

See more on this topic on AccessMedicine.

Transcript

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[Ms. Heidhausen] This is Katerina Heidhausen, executive editor of Harrison's Principles of Internal Medicine. Harrison's Podclass is brought to you by McGraw Hill's AccessMedicine, the online medical resource that delivers the latest content from the best minds in medicine. And now, on to the episode. 

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[Dr. Handy] Hi, everyone. Welcome back to Harrison's Podclass. We're your co-hosts. I'm Dr. Cathy Handy. 

[Dr. Wiener] And I'm Dr. Charlie Wiener and we're joining you from the Johns Hopkins School of Medicine. 

[Dr. Handy] Welcome to episode 137: a 21-year-old with vaginal discharge. 

[Dr. Wiener] Hey, Cathy. Today's patient is a 21-year-old college student who comes to see you reporting a malodorous vaginal discharge for the last week. She's generally healthy and takes no medications. She has had an IUD in place for three years and does have unprotected intercourse with men and reports three partners over the last six months. 

[Dr. Handy] Has she ever been tested or treated for sexually transmitted infections? 

[Dr. Wiener] She tested negative for HIV prior to college, but she's never had any other tests. 

[Dr. Handy] Tell me more about her symptoms and when was her last period? 

[Dr. Wiener] Her last menses was about two weeks ago, and she reports that it was normal. She typically does not have any vaginal discharge, but over the last week, she's reported a mild gray discharge for which she started wearing a pad and she says the pad smells awful. She has no burning, itching, redness of her vagina, and she's not had intercourse since the discharge has been present. 

[Dr. Handy] Okay, an abnormal vaginal discharge is pretty non-specific. She does need to be tested for routine STIs given her risks. However, her discharge should also raise consideration of Trichomonas and bacterial vaginosis, or BV. Typically, an abnormally increased amount or an abnormal odor of the discharge is associated with one or both of these conditions. 

[Dr. Wiener] What about the things I always hear about like gonorrhea, chlamydia, herpes, or candida? 

[Dr. Handy] Well, I already mentioned that she should have testing for routine STIs, including chlamydia and gonorrhea. Cervical infection with N. gonorrhea or C. trachomatis usually does not cause an increased amount or abnormal odor of discharge unless there's a concomitant cervicitis. Vulvar conditions, such as genital herpes or vulvovaginal candidiasis can cause vulvar pruritus, burning, irritation, or lesions, as well as external dysuria as urine passes over the inflamed vulva, or areas of epithelial disruption or vulvar dyspareunia. Tell me about her physical examination. 

[Dr. Wiener] Her vital signs are normal, she's afebrile. Most of her exam is totally normal, but I'll give you a little bit more on her GYN exam. Her vulva and her perineum have no ulcerations or fissures. There is a thin, white, or light gray discharge in her vagina. Her cervix does not look inflamed on speculum examination, and there does not appear to be mucus coming from the cervical os. 

[Dr. Handy] So really normal except for the discharge that's noted. So what's the question? 

[Dr. Wiener] Okay, well, the question's asking, which of the following would be diagnostic of her likely condition? Option A. is adherent white plaques in the vagina. Option B. is clue cells on microscopy of the discharge. Option C. is colpitis macularis or a strawberry cervix. Option D. is prominent lactobacilli on Gram stain of the discharge. And option E. is a vaginal discharge pH of less than 4.0. 

[Dr. Handy] Well, first, we have to discuss the diagnosis, and then can talk about how it would be diagnosed. Based on the history and physical, the most likely diagnosis is bacterial vaginosis. 

[Dr. Wiener] Tell me more about that. 

[Dr. Handy] So bacterial vaginosis, or BV is a syndrome rather than a true sexually transmitted infection. It's characterized by symptoms of vaginal malodor and increased homogenous, low-viscous, white-grade discharge that uniformly covers the vaginal mucosa. Culture of vaginal fluid has grown a number of different organisms, including Gardnerella vaginalis, Mycoplasma hominis, and several anaerobic bacteria. But the unifying pathophysiology seems to be an alteration of the vaginal microbiome, with a notable decrease in the lactobacillus species that constitute most of the normal vaginal microbiota and maintains a low vaginal pH, which helps protect against cervical and vaginal infections. Also, points to know, one, never sexually active women do not get BV, two, douching is a risk factor for BV, and three, treating male partners of women with BV does not reduce the rate of recurrence. 

[Dr. Wiener] Interesting, so that's why you say it's more of a syndrome than a true STI. I also love that this is another example of an altered microbiome being associated with risk of disease. Besides the obvious discomfort, are there other potential risks of having BV? 

[Dr. Handy] Yeah, there are serious related issues. So BV, as well as Trichomonas and vulvovaginal candidiasis, have all been associated with increased risk of acquisition of HIV infection. BV promotes HIV transmission from HIV-infected women to their male sex partners. BV early in pregnancy independently predicts premature onset of labor. And finally, BV can also lead to anaerobic bacterial infection of the endometrium and salpinges. 

[Dr. Wiener] Okay, so given that you think she has BV, what's the answer in this question? 

[Dr. Handy] Yeah, so the answer is B. So to diagnose the condition, you'd see clue cells on microscopy of the discharge. 

[Dr. Wiener] What are clue cells, and how else do you diagnose BV? 

[Dr. Handy] Clue cells are vaginal epithelial cells coated with coccobacillary organisms, which have a granular appearance and indistinct borders that are visualized on a wet mount of vaginal secretions. 

[Dr. Wiener] Are they diagnostic of BV? 

[Dr. Handy] BV is conventionally diagnosed clinically with the Amsel criteria which include any three of the following four clinical abnormalities. So one, objective signs of increased white homogenous vaginal discharge. Two, a vaginal discharge pH of greater than 4.5. Three, liberation of a distinct fishy odor immediately after vaginal secretions are mixed with a 10% solution of KOH. And four, microscopic demonstration of clue cells. 

[Dr. Wiener] Okay, so she meets the diagnosis of BV if those clue cells are present. One of the wrong answers is related to vaginal pH, you want to talk a little bit more about that? 

[Dr. Handy] Yeah, typical vaginal discharge has a pH that's less than 4.5, but you see elevated pH in the discharge of patients with BV and Trichomonas. 

[Dr. Wiener] Once you've diagnosed BV, how do you treat it? 

[Dr. Handy] You can treat it with either oral metronidazole or topical therapy with either metronidazole or clindamycin. 

[Dr. Wiener] Okay, before we finish, why don't you just quickly run through the other incorrect answers? You've already mentioned pH. 

[Dr. Handy] Adherent white plaques in the vagina is typical of vulvovaginal candidiasis. Colpitis macularis or strawberry cervix is a rare sign of inflammation and is typical of Trichomonas, not BV. And, finally, as I mentioned earlier, BV is characterized by a reduction, not an increase in the number of vaginal lactobacilli. 

[Dr. Wiener] Okay, so the teaching points of today's case are that bacterial vaginosis or BV is a disorder characterized by an altered vaginal microbiome. Symptoms are of a malodorous vaginal discharge, without prominent inflammation. The diagnosis is comprised of the typical clinical findings and the presence of clue cells on microscopy. 

[Dr. Handy] And you can find this question and others like it on Harrison's Self-Review, and you can read more about it in the chapter on sexually transmitted infections. Visit the show notes for links to helpful resources, including related chapters and review questions from Harrison's, available exclusively on AccessMedicine. If you enjoyed this episode, please leave us a review so we can reach more listeners just like you. Thanks so much for listening. 

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