Thrush: types, symptoms and treatment
Thrush is an overgrowth of a yeast that lives harmlessly on most of us until something upsets the balance. It shows up in the vagina, under the foreskin, in the mouth and in skin folds, and each form looks different. This page sets out how thrush is recognised, what a pharmacy can supply, when a prescription is involved and which signs mean the diagnosis needs to be checked rather than assumed.
What are the symptoms of thrush?
Vaginal thrush causes itching and soreness around the vulva and vaginal opening, often with a thick white discharge that is usually not foul-smelling. Passing urine can sting where the skin is raw, and sex can be uncomfortable. The skin may look red and swollen, and small splits can appear.
In men, thrush usually affects the head of the penis and the foreskin: redness, itching, a blotchy rash, sometimes a white build-up under the foreskin and soreness when pulling it back. Oral thrush shows as creamy white patches on the tongue, palate or inner cheeks that leave a raw, sometimes bleeding surface when wiped, along with soreness and altered taste. In skin folds, under the breasts or in the groin, it appears as a moist red rash with a scaly edge and small satellite spots.
None of these patterns is unique to yeast, which is why symptoms that do not settle with treatment should be looked at rather than treated again.
What triggers an episode?
Candida species, most often Candida albicans, are part of the normal flora of the mouth, gut and vagina. Thrush happens when conditions let the yeast multiply beyond its usual share, not because something dirty has been introduced.
The classic trigger is a course of antibiotics, which clears bacteria that normally keep yeast in check. Other common contributors are pregnancy and the higher oestrogen levels that go with it, poorly controlled diabetes, medicines that suppress the immune system, chemotherapy, and inhaled corticosteroids used for asthma when the mouth is not rinsed after each dose. Dentures that fit poorly or are not cleaned well predispose to oral thrush, as do a dry mouth and smoking.
Local factors matter too: tight synthetic underwear, staying in damp swimwear, scented soaps, shower gels and vaginal washes all irritate skin and disturb the protective flora. Thrush is not classed as a sexually transmitted infection, although it can be passed between partners, and partners are usually only treated when they have symptoms themselves.
What can a pharmacy supply?
For a straightforward, previously diagnosed episode of vaginal thrush, an Irish pharmacy can supply antifungal treatment without a prescription; the pharmacist decides what is appropriate after asking about your symptoms, your age, pregnancy and any other conditions. Typical options are a clotrimazole cream or pessary used vaginally, and oral single-dose treatment where suitable.
For thrush affecting the skin or the penis, antifungal creams such as clotrimazole or miconazole are available at a pharmacy. Mild oral thrush in adults is often treated with a gel or suspension applied in the mouth. A plain emollient used instead of soap helps sore skin heal.
Pharmacists routinely refer rather than supply in defined situations: a first-ever episode, pregnancy, recurrent episodes, abnormal bleeding, pelvic or lower abdominal pain, fever, a foul-smelling discharge, symptoms in a child, or treatment that has already failed. That referral is not caution for its own sake; it is how a different diagnosis gets caught.
When is a prescription involved?
A prescription comes into it when thrush is severe, when it keeps returning, when it affects someone whose immune system is weakened, or when the oral or oesophageal form needs systemic treatment. In those situations a doctor may prescribe an oral antifungal over a longer period, or a maintenance schedule for recurrent vaginal thrush.
Oral antifungals are not neutral medicines. Fluconazole and itraconazole interact with a long list of other drugs, including some statins and anticoagulants, and they are avoided or handled differently in pregnancy and in liver disease. That is precisely why a doctor reviews the full medication list before a longer course is started.
Recurrent vaginal thrush, usually defined as four or more episodes in a year, is worth confirming with a swab before committing to months of treatment, because a proportion of women treating themselves repeatedly turn out to have a different cause. Blood glucose is usually checked as well, since undiagnosed diabetes shows itself this way surprisingly often.
When do I need medical help without delay?
Call 112 or 999, or go to an Emergency Department, if a mouth or throat infection is making it hard to swallow your own saliva or hard to breathe, if you develop a high fever with severe pain and rapidly spreading redness, or if you become confused or very drowsy while unwell. Those are not features of ordinary thrush.
Arrange an assessment the same day if you are pregnant and have new vaginal symptoms, if there is lower abdominal or pelvic pain, fever, bleeding between periods or after sex, or a discharge that smells offensive. Get medical advice promptly if you are having chemotherapy, take medicines that suppress the immune system, or have poorly controlled diabetes, because in those circumstances a yeast infection can spread beyond the surface.
See a doctor rather than repeating treatment if two courses have not worked, if this is a first episode you have never had confirmed, if a baby is affected, or if painful ulcers rather than white patches are the main problem.
What thrush can be confused with
Bacterial vaginosis produces a thin, greyish discharge with a fishy smell and usually little itching, and it is treated with completely different medicines. Trichomoniasis can cause a frothy, yellow-green discharge with soreness and is a sexually transmitted infection requiring partner treatment. Chlamydia and gonorrhoea often cause no symptoms at all, which is why testing is offered when the picture does not fit.
Itching without discharge is frequently not yeast. Contact dermatitis from soaps, wipes or pads is common, and in women past the menopause, thinning of the vulval and vaginal tissue causes dryness and soreness that antifungals will not touch. Lichen sclerosus causes persistent itching with pale, fragile skin and needs a proper diagnosis and follow-up.
In the mouth, white patches that cannot be wiped away, or a single persistent ulcer or patch that does not heal, are not thrush and need to be examined, particularly in smokers.
Reducing the chance it returns
Prevention is mostly about not disturbing what already works. Wash the vulva with water or an unperfumed emollient rather than soap, skip vaginal washes and douches entirely, and avoid scented products, including scented liners and wipes. Cotton underwear and getting out of wet swimwear reduce the warm, damp conditions the yeast prefers.
If you use an inhaled corticosteroid, rinse your mouth and spit out after each dose, and use a spacer where one is provided. Denture wearers should remove and clean dentures every night. If diabetes is part of the picture, better glucose control does more for recurrent thrush than any cream.
Yoghurt and probiotics are often recommended by word of mouth. The evidence is inconsistent and they are not a substitute for treatment, though they do no harm taken by mouth. Applying yoghurt vaginally is not advised. If episodes keep returning despite all of this, the sensible next step is a swab and a review, not another packet from the shelf.
Is thrush a sexually transmitted infection?
No. Thrush is an overgrowth of yeast that is already present on the body, and it occurs in people who have never had sex. It can sometimes be passed between partners, so a partner with symptoms should be treated, but routine treatment of a partner without symptoms is not recommended.
Can I treat thrush myself without seeing anyone?
If you have had thrush confirmed before and the symptoms are the same, a pharmacy can supply treatment after a short conversation. A first episode, pregnancy, recurring episodes, pain, fever, bleeding or a foul-smelling discharge all mean the diagnosis should be confirmed rather than assumed.
Why do I get thrush after antibiotics?
Antibiotics reduce the bacteria that normally keep yeast in check, so the yeast multiplies. It is a common and expected side effect, not a sign that the antibiotic was wrong. Treating the thrush does not mean stopping the antibiotic course early.
Does thrush affect pregnancy?
Thrush is more common in pregnancy because of hormonal changes, and it does not harm the baby. Treatment differs: oral antifungal tablets are generally avoided and local treatment is used instead, so any new vaginal symptoms in pregnancy should be assessed rather than self-treated.
I keep getting thrush. What should happen next?
Four or more episodes in a year is a reason to confirm the diagnosis with a swab, check blood glucose and review contributing factors and medicines. A doctor can then consider a longer or maintenance treatment plan. Repeating over-the-counter courses indefinitely without a confirmed diagnosis is the pattern most likely to hide something else.