Initial assessment
When assessing a patient with vaginal discharge, the clinical approach should begin by characterising associated symptoms,
particularly the presence of odour and irritative symptoms such as pruritus or vulvar burning.
These elements guide diagnostic suspicion and help differentiate between the main aetiologies.
Whenever possible, assessment should include gynaecological examination, vaginal pH measurement and direct microscopy or rapid tests.
Bacterial vaginosis
In the absence of irritative symptoms and in the presence of a strong fishy odour, the most likely diagnosis is bacterial vaginosis.
The discharge is typically greyish-white, thin and homogeneous, uniformly coating the vaginal walls.
Approximately half of women may be asymptomatic.
Treatment is indicated in symptomatic women, in asymptomatic women who are going to undergo gynaecological surgery,
and in pregnant women with a history of preterm birth or second-trimester miscarriage.
The male partner does not require treatment; however, female partners should be treated if they are also affected.
First-line therapy includes oral metronidazole 400–500 mg twice daily for 5–7 days,
metronidazole 0.75% intravaginal gel once daily for 5 days or
clindamycin 2% intravaginal cream once daily for 7 days.
As an alternative, oral clindamycin 300 mg twice daily for 7 days may be used.
In recurrent forms, it is useful to consider intravaginal metronidazole twice weekly for 16 weeks.
Vulvovaginal candidiasis
When the discharge is odourless and accompanied by irritative symptoms, such as pruritus and vulvar burning,
vulvovaginal candidiasis should be suspected.
The discharge is white, curd-like and thick, adherent to the vaginal walls,
often associated with erythema, oedema, fissures and satellite skin lesions.
Treatment may be with oral fluconazole 150 mg as a single dose or with intravaginal antifungals,
such as clotrimazole — 500 mg as a single dose or 200 mg for 3 days,
miconazole — 1200 mg single dose or 400 mg for 3 days or econazole 150 mg as a single dose.
In recurrent cases, defined as four or more symptomatic episodes per year,
an induction phase with oral fluconazole 150–200 mg once daily for 3 consecutive days is recommended,
followed by maintenance with oral fluconazole 100–200 mg once weekly for 6 months.
In pregnancy, oral therapy should be avoided and only topical formulations should be used, preferably for 7 days.
Trichomoniasis
In the presence of discharge with a fetid odour and frothy characteristics in more than 70% of cases,
or yellow-green features in 10 to 30%, trichomoniasis should be suspected.
Symptoms may include pruritus, dysuria, vulvar erythema and a “strawberry” cervix.
Treatment is mandatory in all symptomatic women or those with a confirmed diagnosis,
as well as in their sexual partners.
The first-line regimen is oral metronidazole 400–500 mg twice daily for 7 days,
with alternatives including oral metronidazole 2 g as a single dose or oral tinidazole 2 g as a single dose.
In recurrent cases, prolonged regimens of nitroimidazoles at higher doses may be used.
It is essential to avoid alcohol intake during treatment and for 48 hours after metronidazole
— 72 hours in the case of tinidazole.
Aerobic / inflammatory vaginitis
In cases of aerobic vaginitis, the discharge is typically abundant, purulent and odourless,
associated with vulvar burning and superficial dyspareunia.
First-line treatment consists of intravaginal clindamycin 2% for 7–21 days,
and intravaginal hydrocortisone 300–500 mg may be added for the same period in more severe cases.
If concomitant atrophy is present, topical oestrogen therapy should be considered.
Special situations
The approach should be adjusted in the context of pregnancy, immunosuppression or recurrent episodes.
In pregnancy, topical regimens with a better safety profile should be preferred.
In recurrent cases, laboratory confirmation of the diagnosis is essential to exclude other causes
and guide treatment appropriately.
