A history, including a sexual history, is necessary to try to determine the cause. Causes of vaginal discharge can be categorised as physiological, infective (non-sexually), infective (sexually) and non-infective.
Details to gather include the timing of onset - is the discharge new and if not, why has the patient presented now? Has it changed in colour, frequency or odour?
If it is new, the history of the discharge is important together with a sexual history. Has there been a recent change in partner?
Determine whether the patient is using contraception and whether there are any associated symptoms, such as itch, superficial or deep dyspareunia, lower abdominal pain or fever.
Is the discharge blood-stained? Is there any postcoital bleeding or menstrual irregularity? Also, check that the patient's smears are up to date.
Examination is essential if a cervical aetiology, STI, PID or non-infective cause is suspected. If a simple candidiasis is suspected, it is reasonable to test this hypothesis with appropriate treatment.
Physiological causes are common and consist of cervical mucus, local bacterium, secretions and menstrual fluid. In women of reproductive age, fluctuating levels of estrogen and progesterone contribute to this process. It is generally non-offensive and often white or clear.
The two infections that fall into this category are bacterial vaginosis and candidiasis. Bacterial vaginosis tends to lead to a fishy discharge and is due to an overgrowth of anaerobic bacteria replacing the normal vaginal flora, leading to an increase in pH. Candidiasis is another common presentation and patients may state that they have thrush. This is generally based on previous experience. The discharge is often white and there may be associated itch.
It may be triggered by recent use of antibiotics, steroids or long-term immunosuppressants. Think about underlying immunosuppression or consider diabetes mellitus if the infection persists.
Infections to consider include chlamydia, gonorrhoea and trichomonas. These are all transmitted sexually, thus the patient's history may guide diagnosis. If detected, patients require prompt treatment, screening for other STIs, partner notification and/or contact tracing.
Causes in the non-infective category include rectovaginal fistulae, foreign bodies, such as tampons or condoms, cervical ectopy, polyps and genital tract malignancy.
Allergy to lubricants or spermicides can also present with vaginal discharge.
- Dr Singh is a GP in Northumberland.