Differential Diagnosis for Fishy Smelling Vaginal Discharge
- Single Most Likely Diagnosis
- Bacterial Vaginosis (BV): This is the most common cause of fishy smelling vaginal discharge. BV is a bacterial infection that occurs when the natural balance of bacteria in the vagina is disrupted, leading to an overgrowth of anaerobic bacteria. The fishy odor is due to the production of amines by these bacteria.
- Other Likely Diagnoses
- Trichomoniasis: A sexually transmitted infection caused by the parasite Trichomonas vaginalis. It can cause a foul-smelling vaginal discharge, which may be greenish or yellowish in color.
- Vulvovaginal Candidiasis: Although typically associated with a yeasty odor, some cases of vulvovaginal candidiasis can present with a fishy smell, especially if there is a secondary bacterial infection.
- Do Not Miss Diagnoses
- Pelvic Inflammatory Disease (PID): While PID may not always present with a fishy smelling discharge, it is a serious condition that can cause significant morbidity if left untreated. PID is an infection of the upper genital tract that can be caused by a variety of bacteria, including those that cause sexually transmitted infections.
- Cervical Cancer: Although rare, cervical cancer can cause abnormal vaginal discharge, which may have a foul odor. It is essential to rule out this diagnosis, especially in women who are not up to date with their cervical cancer screening.
- Rare Diagnoses
- Desquamative Inflammatory Vaginitis (DIV): A rare condition characterized by a purulent vaginal discharge and inflammation of the vaginal walls. The discharge may have a foul odor.
- Foreign Body: The presence of a foreign body in the vagina, such as a retained tampon, can cause a foul-smelling discharge.
- Rectovaginal Fistula: An abnormal connection between the rectum and vagina can cause fecal matter to enter the vagina, resulting in a foul-smelling discharge.