How is vaginal candidiasis diagnosed?

• A. Positive whiff test
• B. Clue cells on saline
• C. KOH prep shows budding yeast or pseudohyphae
• D. Elevated pH

Answer: (C)

Diagnosing vaginal candidiasis hinges on locating fungal elements in the discharge. A potassium hydroxide (KOH) prep is used because it clears debris and makes organisms easier to see. Candida typically appears as budding yeast organisms and pseudohyphae on microscopy, which is the hallmark that confirms the infection in the right clinical context. By contrast, a positive whiff test and clue cells point to bacterial vaginosis, and vaginal pH is usually normal in candidiasis but elevated in BV or trichomoniasis. So the visual evidence of budding yeast with pseudohyphae on a KOH prep best confirms vaginal candidiasis.