Question
Which of the following is most likely to be associated with a vaginal pH of 4?
| A. |
Atrophic vaginitis |
| B. |
Trichomanas vaginatis |
| C. |
Candidal vaginitis |
| D. |
Gardenella vaginitis |
|
Correct Answer » C Explanation |
 |
Clinical Reasoning for the Correct Answer:
– Normal vaginal pH in reproductive-aged women is 3.8–4.5, maintained by lactobacilli.
– Candidal vaginitis occurs at a normal or slightly acidic pH (≤4.5).
– Candida species do not raise the pH significantly because they do not disrupt lactobacilli activity.
– Vaginal pH of 4 is consistent with Candida infection, not with those causing an elevated pH.
Why Option A is Incorrect (Atrophic vaginitis):
– – Atrophic vaginitis occurs in postmenopausal women due to estrogen deficiency.
– pH is elevated (> 5) due to loss of lactobacilli and decreased estrogen.
Why Option B is Incorrect (Trichomonas vaginitis):
– – Trichomonas vaginalis is a protozoan causing vaginal pH elevation (> 4.5).
– Green/yellow frothy discharge and strawberry cervix are classic findings.
Why Option D is Incorrect (Gardnerella bacterial vaginosis):
– – Bacterial vaginosis due to Gardnerella vaginalis leads to vaginal pH > 4.5.
– Fishy odor and clue cells with loss of lactobacilli are typical.
High‑Yield Synopsis:
Vaginal pH in Common Vaginal Infections
– Normal vagina: pH 3.8–4.5 due to lactobacilli.
– Candidal vaginitis:
– pH: usually normal (≤4.5)
– Discharge: Thick, white, “cottage cheese”
– Pruritus common
– Bacterial vaginosis (Gardnerella):
– pH: >4.5
– Gray, thin, fishy-smelling discharge; clue cells
– Minimal inflammation
– Trichomonas vaginitis:
– pH: >4.5
– Profuse, green-yellow, frothy discharge; strawberry cervix
– Atrophic vaginitis:
– pH: often > 5 postmenopausally due to reduced estrogen
– Dryness, irritation, dyspareunia
Key Discriminators:
– Low/normal pH (≤4.5): Candidal vaginitis
– Elevated pH (>4.5): Trichomonas, bacterial vaginosis, atrophic vaginitis
