Vaginal discharge refers to discharge from the genital tract, which predominantly does not consist of blood. It may involve physiological discharge or non-physiological ‘pathological’ discharge. The cause of abnormal discharge can lie anywhere in the genital tract (vagina, vulva, cervix, uterus, ovary) and hence it is also called genital discharge.
Physiological discharge is produced due to a number of processes:
- Shedding / desquamation of the surface epithelium layers of the vaginal wall. Its prevalence is particularly influenced by combined oestrogen and progesterone input, i.e. during the second half of the menstrual cycle. This follows the first half of the cycle during which, under influence of oestrogens only, the vaginal wall becomes thicker.
- Production of cervical mucus. The columnar epithelium of the endocervical crypts produces cervical mucus, particularly with high oestrogen levels.
- Transudation. The vaginal wall allows fluid to pass through from the underlying blood vessels. If blood flow increases (e.g. with sexual arousal, pregnancy), the quantity of transudate also increases. This results in the discharge having a thinner appearance and consequently is more likely to cause symptoms.
Also consider that semen may also form part of the discharge, depending on the frequency of sexual contact and possible condom use.
Normally, 1-3 ml of discharge per 24 hours is produced in the vagina (in the period between menarche and menopause). There are considerable differences in the quantity and composition of discharge between women, but also per woman there can be differences during a cycle or between cycles. Therefore, there is a lot of variation to what is considered ‘normal’.
It is possible that a woman, at some stage, experiences physiological vaginal discharge as uncomfortable. However, if a woman visits the GP with a complaint about discharge this should normally be a reason to carry out further diagnostic investigations. Genital discharge is a symptom and with your history-taking and specific gynaecological examination, combined with an analysis of the discharge, you can often determine the cause.
As previously mentioned, the cause of abnormal vaginal discharge can be located anywhere along the genital tract. However, in the majority of cases, the cause is an infection, either vaginal or cervical. This is one of the most common gynaecological problems that patients present with in a GP practice.
An infection with Candida albicans is the most prevalent disorder, followed by bacterial vaginosis. Infections of Trichomonas vaginalis and Chlamydia trachomatis are less common, while gonorrhoea occurs only rarely. The latter three are sexually transmitted diseases (STDs). This means that the partners should also be treated. Chlamydia and gonorrhoea may give rise to severe complications and should always be treated.
With your history-taking and examination you can determine the characteristics of the symptoms and discharge. Certain potential causes of a vaginal infection will become more likely or actually less likely candidates for the root of the problem.
History-taking
Bear in mind that discharge symptoms may be accompanied by embarrassment or fear of a venereal disease. Take this into account when choosing the manner in which you take the history.
To exclude STDs amongst other things, it is important to ask the following questions:
- Is there any itching or irritation?
- Duration of symptoms?
- Colour and odour of the discharge?
- Unprotected sexual contact?
- Different sexual contacts (or a partner with different sexual contacts)?
- Does partner have any symptoms?
Gynaecological examination [Figures 62, 63, 64]
- Prepare all materials for discharge investigation and all materials and instruments required for a speculum examination.
- pH-indicator strip
- Spatula for discharge sampling (or inoculation loop)
- Glass slides
- Cover slip
- Physiological salt solution (NaCl 0.9%)
- KOH 10-20% solution
- Microscope
- Possibly (if an STD is suspected)
- Cotton buds (thick) or Cervex-brush
- Culture medium for chlamydia, in tube
- Transport medium for gonorrhoea, in tube
Write name and date of birth on the slides and the tubes!
Figure 62
Figure 63
Figure 64
- Conduct external inspection and pay particular attention to redness, excoriation, and ‘white coating / discharge’.
- Insert the speculum as described in chapter 3 and assess:
- Vaginal wall
- Cervix
- Discharge: colour and consistency (see table)
- Collect a sample of discharge with the spatula, for further analysis (as described below).
Determine the pH by putting a drop of discharge onto the pH-indicator strip.
Conduct the amine test: i.e. add a drop of KOH to some discharge (this can also be done concomitantly with the KOH slide preparation) and assess the odour. The test is positive if you smell ‘amines’ (fishy smell). This points to a Gardnerella vaginalis infection.
Subsequently prepare:
1 direct (unstained) samples:
KOH slide
- Using a spatula, take a sample of discharge from the vaginal wall.
- Put a drop of discharge onto the slide.
- Add 1-2 drops of KOH 10-20% solution.
- Mix the discharge with the KOH.
- Spread the mixture across the slide.
NaCl slide
- Using a spatula, collect some discharge from the posterior fornix.
- Put a drop of discharge onto the slide.
- Add a couple of drops NaCl 0.9% solution.
- Mix the discharge with the NaCl solution.
- Cover the slide with a cover slip.
Analyse the slides as soon as possible under a microscope. The NaCl slide should be analysed first; keep it warm if possible as this will increase the chance of detecting trichomonas flagellates in the case of trichomoniasis.
- Look out for:
- Leucocytes
- Epithelial cells
- ‘Clue cells’
- Bacteria
- Trichomonads
- Hyphae.
If there are indications that the infection may be caused by gonorrhoea or chlamydia (or another STI) you should also carry out an additional investigation (remember to investigate the partner as well – see further on – and treat this person, if necessary).
2 Additional discharge investigation [Figures 65, 66, 67]
Diagnostics for gonorrhoea
- Make use of the gonorrhoea sampling kit available from the microbiology laboratory and follow its instructions for correct collection of material.
- Using a thick cotton bud, collect some discharge from the external os of the endocervix (possibly also the urethra and anus).
- Smear the bud onto a slide or place it in a dry tube (Stuart culture emdium: the laboratory staff will use it to prepare a sample later).
and / or
- Using a cotton bud, remove some discharge from the external os and rinse this in the medium for PCR analysis (this is often a complete sampling kit).
If it is necessary to determine the sensitivity for specific antibiotics, a sample can be cultured.
- using a cotton bud, the collected material is placed in preservation medium / culture medium and sent off.
Diagnostics for chlamydia
– Make use of the chlamydia sampling kit available from the microbiology laboratory and follow its instructions for correct collection of material.
- Insert a cotton bud or cervical sampling brush 2-4 cm into the cervical canal.
- Rotate it for 3-5 seconds.
- Rinse the cotton bud or Cervical sampling brush in the medium contained in the tube. This is used for PCR analysis of the discharge.
- Take out the cotton bud or the cervical sampling brush.
NB. in some laboratories chlamydia is determined from urine, using the PCR technique. This is done particularly when screening symptom-free women for chlamydia.
Sampling for ‘bacterial culture’
- Using a thick cotton bud, take material from the posterior fornix or from the external os of the cervix.
- Place the cotton bud in preservation medium.
- Remove the speculum and assist the patient from the examination table.
Figure 65
Figure 66
Figure 67
For the sake of completeness, we will also describe how to collect material to diagnose gonorrhoea and chlamydia in a male patient. For more information on examination of the external genitalia of the male we refer you to the ‘The abdominal examination’.
Diagnostic procedure for gonorrhoea
- Using a cotton bud, collect some discharge from the front end of the urethra.
- Make a smear on a slide or place the cotton bud in a dry tube, so that the laboratory staff can use it to prepare a slide later.
- Using a cotton bud, remove some discharge from the front end of the urethra and rinse this in the medium for PCR analysis (this is often a complete sampling kit). If it is necessary to determine the sensitivity for specific antibiotics, a sample can be cultured.
- The collected material should be placed together with the cotton bud in the preservation medium / culture medium and sent off.
Diagnostic procedure for chlamydia
- Insert a thin cotton bud 2-4 cm into the urethra.
- Rotate the bud for 3-5 seconds.
- Rinse the cotton bud in the medium contained in the tube. This is used for PCR analysis.
- Remove the cotton bud.
Characteristics of the vaginal discharge with different disorders
Normal
Consistancy: non-homogeneous slimy
Colour: clear to white
Smell: odourless
Gas formation: n.a.
pH: approx. 4
Amine test: –
Microscopy: Doderlein flora
Candidiasis
Consistancy: crumbly curdled milk
Colour: white
Smell: odourless
Gas formation: n.a.
pH: approx. 4
Amine test: –
Microscopy: yeast
Gardnerella vaginalis
Consistancy: paste-like thick liquid
Colour: grey-white
Smell: unpleasant smell
Gas formation: sometimes
pH: 4.5 – 5.5
Amine test: +
Microscopy: clue cells, few leucocytes
Trichomoniais
Consistancy: watery, foamy
Colour: yellow or yellow-green
Smell: unpleasant smell
Gas formation: often
pH: 5 – 6
Amine test: (+)
Microscopy: Trichomonads, many leucocytes
Chlamydia trachomatis
Consistancy: non-specific
Colour: variable (sometimes pus from endocervix)
Smell: sometimes unpleasant
Gas formation: n.a.
pH: sometimes normal
Amine test: –
Microscopy: many leucocytes