Oral thrush (oral candidiasis)
The candida fungus lives in the mouth of roughly one healthy person in two and gives no sign of itself: saliva, the neighbouring bacteria and the immune…
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Medicines commonly prescribed for Oral thrush (oral candidiasis)
For informational purposes only. Always consult a doctor before using any medicine.
Dosage form: CAPSULE, 100 mg fluconazoleActive substance: fluconazoleManufacturer: Laboratorios Normon S.A.Prescription requiredDosage form: CAPSULE, 200 mgActive substance: fluconazoleManufacturer: Vinci Farma, S.A.Prescription requiredDosage form: CAPSULE, 50 mgActive substance: fluconazoleManufacturer: Tecnimede España Industria Farmaceutica S.A.Prescription required
The candida fungus lives in the mouth of roughly one healthy person in two and gives no sign of itself: saliva, the neighbouring bacteria and the immune system keep it in check. Thrush starts where that balance is upset — after a course of antibiotics, because of an inhaler, from a dry mouth, from a poorly fitting denture, or from an illness that has weakened the defences. Treating the fungus alone therefore achieves little: if the cause stays, the coating comes back within a month or two. And there is one more reason for this page: white in the mouth is not always thrush, and some white patches are dangerous and need an entirely different approach.
What it looks like and how it feels
The most recognisable picture is white or creamy-yellow patches that look like cottage cheese or curdled milk. They sit on the tongue, the inside of the cheeks, the roof of the mouth and sometimes the gums and throat. The feature that identifies them: the coating rubs off — with gauze, the edge of a spoon, a toothbrush — and underneath it leaves bright red, inflamed lining that occasionally bleeds a little. If a white patch will not scrape away, it is not thrush, and there is a section on that below.
There may be no coating at all, though. The second form is the red one: the tongue turns smooth, glazed and sore, and under a removable denture the roof of the mouth looks evenly reddened, exactly to the edge of the plate. This form goes unnoticed for years, because the burning gets blamed on nerves or on spicy food.
What the person usually notices:
- burning or soreness in the mouth, especially with sour, spicy or hot food;
- taste has dulled, or there is an unpleasant or metallic taste;
- dryness and a cotton-wool feeling in the mouth;
- pain on eating and drinking, so bland, cool food gets chosen instead;
- cracks and crusts at the corners of the mouth that are slow to heal.
Oral thrush in adults is not passed from person to person: everyone carries the fungus already, and the issue is the conditions, not the contact.
In babies and breastfeeding mothers
Thrush is common in babies, and in the first months of life it says nothing bad in itself — the defences of the mouth are still settling in. Parents notice white plaques on the tongue and cheeks, restlessness at the breast, refusal to feed, and sometimes a stubborn nappy rash at the same time, which is the same fungus at the other end.
The question parents most often have is whether it is thrush or leftover milk. Telling them apart is simple: milk sits on the tongue only, wipes away with damp gauze, and the lining beneath it is normal and pink. A thrush coating needs some effort to shift, is on the cheeks too, and leaves redness underneath.
Mother and baby pass the fungus back and forth, so both need treating at the same time even if only one of them has any complaint. In the mother, nipple thrush causes a stabbing or burning pain that begins during the feed and carries on afterwards, going deep into the breast; the nipple itself may look normal, or shiny and flaky. Breastfeeding does not need to stop — the two of you need treating together.
White in the mouth is not always thrush
This is the most important part of the page. Several conditions look similar, are treated differently, and one of them is dangerous:
- leukoplakia — a white patch or plaque that will not scrape off. Antifungal medicine does nothing to it. Some of these patches change over time, so a dentist examines them and takes a biopsy where needed;
- cancer of the lining of the mouth — a white or red patch, an ulcer that will not heal, a lump or pain lasting more than three weeks. Smoking and alcohol raise the risk. This is the one that cannot wait;
- oral lichen planus — white lacy streaks on the cheeks, often matching on both sides, sometimes with painful raw areas;
- geographic tongue — pink islands with a pale rim that change shape from week to week: harmless and needing no treatment;
- aphthous ulcers — single round sores with a white base and a red rim, very painful, healing in a week or two. They have nothing to do with the fungus.
The rule is simple: a coating that will not rub off, or a patch that lasts longer than three weeks, is a reason to see a dentist or doctor, not a reason to try another ointment.
Why the fungus overgrows
Thrush is nearly always the consequence of something else. The commonest causes:
- antibiotics, particularly long courses: they clear away the bacteria that were holding the fungus back;
- steroid inhalers for asthma and COPD when the mouth is not rinsed after a dose, because the drug settles on the lining;
- removable dentures, especially if worn at night, cleaned poorly, or gone loose and rubbing;
- a dry mouth — from medicines, dehydration, radiotherapy to the head and neck, or Sjögren's syndrome. Saliva washes the fungus away, and without it the fungus has a free hand;
- diabetes with high blood sugar, steroid tablets, chemotherapy, and any state of weakened immunity;
- lack of iron, vitamin B12 or folate, smoking, and a poor monotonous diet.
The adult in whom thrush appears with no visible cause, or keeps coming back, or takes up half the mouth deserves a separate mention. That is not "low immunity" in some vague sense: it is a reason to check the blood sugar and to discuss with a doctor testing for the conditions that weaken the defences, HIV among them. Thrush of that kind often turns out to be the first visible sign.
What is used to treat it
The mainstay is antifungal medicine applied locally: a suspension or a gel spread over the lining and held in the mouth as long as possible before swallowing, so that it works where it needs to. The course is continued for a few days after the coating has gone, otherwise it returns. One of the gels used interferes with blood-thinning medicines and with some cholesterol drugs, so tell the doctor in advance everything you are taking.
If the coating is extensive, does not yield to local treatment, or the person is on chemotherapy or has weakened immunity, an antifungal in tablet form is prescribed. The particular medicine, the dose and the length of the course are the doctor's choice.
Treatment does not end with the medicine. During the course the denture comes out at night and is disinfected separately, otherwise the fungus sits out the treatment on the plastic and returns to the mouth. Teats and bottles are sterilised. Mother and baby are treated together. And most important of all, the cause is dealt with: inhaler technique is corrected, blood sugar is brought into order, the denture is refitted, iron deficiency is looked for. If radiotherapy to the head and neck is planned, dental treatment needs finishing beforehand — afterwards any work on the jaw becomes far riskier.
The daily care that keeps it away
- brush twice a day, and if no teeth are left, go over gums, palate and tongue with a soft brush;
- rinse the mouth and spit out after every dose from a steroid inhaler; a spacer reduces how much drug settles on the lining;
- take the denture out at night, brush it and keep it in a disinfecting solution; if it is loose, go to the dentist rather than padding it out;
- rinse the mouth after eating and after taking medicines;
- drink enough water if the mouth is dry, and review with the doctor any medicines causing it;
- stop smoking — it noticeably cuts the rate of recurrence;
- sterilise teats and bottles, and do not suck a dummy before giving it to the baby;
- see a dentist regularly, even with no natural teeth left;
- keep long-term conditions under control, diabetes above all.
When to see a doctor without delay
See a doctor the same day if:
- swallowing has become painful, or food seems to hold up behind the breastbone — the fungus may be spreading down the oesophagus, and that needs tablets;
- thrush appears in an adult with no clear reason, or comes back for a third time;
- the coating is spreading, a fever has started, or the person is on chemotherapy or immune-suppressing treatment;
- a white or red patch will not scrape off and has lasted more than three weeks;
- there is an ulcer in the mouth that will not heal, a lump, or pain that travels to the ear.
In a baby the warning signs are different: refusing breast and bottle for several feeds running, wetting fewer nappies than usual, floppy, with a dry mouth and a sunken soft spot on the head. Those are signs of dehydration and need urgent help; if the baby is going downhill fast, call an ambulance (in Spain, Italy, Portugal, Poland and Ukraine, 112).
Online consultation
Oral thrush is exactly the sort of problem an online appointment suits. From a description and a photograph the doctor can tell a curd-like coating from leftover milk and from a patch that will not scrape off, say what to do today and, more to the point, work out where it all came from: going through the list of medicines, checking inhaler technique, asking about blood sugar, dentures and recent antibiotics. It is particularly useful for breastfeeding mothers, because pain in the breast during a feed is so often put down to poor latch, and the conversation helps make clear that two people need treating.
What an online appointment cannot replace: examination of the mouth when a coating will not come off or a patch has lasted more than three weeks; a dental visit when the denture is the problem; blood tests when the doctor is hunting for the cause. And with signs of dehydration in a child what is needed is not a chat window but an ambulance.
This material is for information only and does not replace medical advice.
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