Differential Diagnosis for Vaginal Discharge

The patient presents with a grayish vaginal discharge and a pH greater than 4.5. Based on these symptoms, the following differential diagnoses can be considered:

• Single most likely diagnosis

  • Bacterial Vaginosis (Clue cells): The presence of a grayish discharge with a pH greater than 4.5 is highly suggestive of bacterial vaginosis. Clue cells, which are vaginal epithelial cells coated with bacteria, are a hallmark of this condition and would be visible on a wet mount preparation.

• Other Likely diagnoses

  • Trichomonas vaginalis: Although less likely given the description of the discharge, Trichomonas vaginalis infection can cause a change in vaginal discharge and an elevated pH. It would be identified by the presence of the motile organism on a wet mount.
  • Yeast infection (Budding yeast): While the pH is not typically elevated in yeast infections, it's not exclusively low either. However, the description of the discharge as grayish is less typical for a yeast infection, which usually presents as a thick, white, cottage cheese-like discharge.

• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)

  • Gonococcal or Chlamydial infection: Although the patient's sexual history and symptoms do not strongly suggest these infections, they are important to consider due to their potential for serious complications, including pelvic inflammatory disease (PID). These would typically be diagnosed through specific cultures or nucleic acid amplification tests rather than a wet mount.
  • Leukocytes in sheets (indicative of an inflammatory process): This finding could suggest an infectious process such as PID or another condition that requires prompt treatment.

• Rare diagnoses

  • Ferning: This is typically seen in normal vaginal secretions when they dry, forming a fern-like pattern under microscopic examination. It's not directly related to the patient's symptoms of abnormal discharge.
  • Other rare infections: Such as those caused by herpes simplex virus or other less common pathogens. These would be considered based on additional symptoms or risk factors not provided in the scenario.