Treating recurring yeast infections

A vaginal yeast infection (vaginal thrush) is an extremely common cause of vaginal discharge - up to 3 in 4 women will have at least one episode during their lives. In most cases, thrush in women settles with simple treatment, either topical (applied to the vagina in the form of pessaries or antifungal creams) or oral (a tablet or tablets). However, some women either have repeated new infections, or find that they still have symptoms because the initial thrush treatment has not been effective.

What causes recurring yeast infections?

Speculum examination showing vaginal thrush

© Mikael Häggström, CC0, via Wikimedia Commons

Of women who develop a first bout of vaginal thrush, about 5 in 100 of them will get problems with recurring thrush. In most cases, the reason why this occurs is not known. Some women just seem more prone than usual to develop thrush. However women with high blood sugar (due to poorly controlled diabetes) and women with weakened immune systems may be more likely to develop recurrent thrush.

There is some debate as to whether women taking hormone replacement therapy (HRT) or birth control pills such as the combined oral contraceptive (COC) pill are more likely to develop a recurring yeast infection - the evidence is not yet clear.

If you have repeated bouts of thrush then one option is simply to treat each bout as and when it occurs. See the separate leaflet Vaginal thrush (Yeast infection) for treatments for thrush.

Recurrent thrush is defined as 4 or more symptomatic episodes per year. If you have four or more episodes of vaginal thrush a year, with at least 2 episodes confirmed by a swab test, your doctor may suggest a different approach.

Before they do this, they may want to exclude another cause for your symptoms. This could include:

• Taking a vaginal swab and sending it the laboratory to check for evidence of thrush or other infection.

• Checking the pH (acidity level) in your vagina using a simple test strip. A lower pH (4.5 or below) makes it more likely that thrush is the cause. A higher pH (above 4.5) makes bacterial vaginosis (BV) or trichomonas infection (a sexually transmitted infection) more likely.

• Other swabs or tests as appropriate.

Treatment for recurrent thrush

Using one of the usual treatments for vaginal thrush (topical treatments or tablets) - but for longer than usual. Your doctor will advise exactly how long to use the treatment for. Vaginal thrush can be treated with over the counter medicines, but as you need a longer course of treatment, your GP will give you a prescription for treatment if you need it.

How the recurring yeast infection is treated will also depend on your preferences and other factors such as whether you can tolerate the treatment, or have ever reacted badly to it, your age and whether you're pregnant (in which case vaginal pessaries will usually be advised). If you're 12-15 years old, or it's not clear whether your symptoms are due to recurrent vaginal thrush, your doctor may recommend a hospital specialist referral.

• The first-line recommended 'induction treatment' is three doses of fluconazole 150 mg tablets (to be taken every 72 hours).

• This is followed by regular 'maintenance treatment' to stop the thrush coming back, with once weekly tablets of fluconazole 150 mg for six months.

If you can't take fluconazole tablets for whatever reason, topical therapy (such as clotrimazole 500 mg vaginal pessary) can be used as induction treatment for 7-14 days, depending on how your symptoms respond. Maintenance treatment would then be a clotrimazole 500 mg vaginal pessary inserted once a week for six months or itraconazole tablets 50-100 mg once daily for six months.

Most women remain clear of thrush during maintenance treatment. If you and your doctor decide maintenance treatment is best for you, this will usually last for six months.

After treatment is stopped, many women remain free of thrush, or only develop the occasional bout again. However, some women return to developing recurring yeast infections. If this happens, the treatment plan can be repeated, and maintenance treatment continued for longer.

Regardless of the treatment you and your doctor agree, it's important to use lifestyle measures to reduce your risk of recurring yeast infections (you can find out more below). In addition, you should speak to your doctor if:

• Your symptoms don't improve with treatment.

• You develop thrush whilst on maintenance treatment. This may indicate that you have a resistant strain of Candida spp. which may require an alternative treatment.

• You become pregnant or are breastfeeding.

• You develop side-effects from the medication.

• You develop new symptoms, such as smelly discharge, ulcers or blisters, abnormal vaginal bleeding or a bloodstained discharge.

• You feel unwell in yourself.

The yeast that causes yeast infections, called Candida spp. such as Candida albicans, thrives in warm, moist, airless environments. General lifestyle changes that help prevent single episodes of vaginal thrush can also help reduce the risk of recurrent thrush.

If you have diabetes, your risk of recurring yeast infections is higher if your blood sugar is consistently high. Working with your diabetes team to bring your blood sugar under control can cut the risk of recurrent bouts of thrush.

If you experience recurring yeast infections, your doctor or nurse may also discuss your current method of contraception with you and suggest a change. There has been talk in the past about the combined oral contraceptive (COC) pill (the birth control pills that contain both oestrogen and progesterone hormones) possibly making recurrent vaginal thrush more likely. However, the evidence around this is a little unclear.