What is mouth thrush?

Oral (mouth) thrush, also known as oral candidiasis is a yeast fungi infection of the genus Candida that develops on the mucous membranes of the mouth. It is most commonly caused by Candida albicans, but may also be caused by other Candida species. Oral thrush causes thick white or cream-coloured deposits, most commonly on the […]

Oral (mouth) thrush, also known as oral candidiasis is a yeast fungi infection of the genus Candida that develops on the mucous membranes of the mouth. It is most commonly caused by Candida albicans, but may also be caused by other Candida species.
Oral thrush causes thick white or cream-coloured deposits, most commonly on the tongue or inner cheeks. The lesions can be painful and may bleed slightly when they are scraped. The infected mucosa of the mouth may appear inflamed and red. Oral thrush can sometimes spread to the roof of the mouth and the back of the throat.
For the majority of us, oral thrush does not cause any serious problem. However, this is not the case for individuals with a weakened immune system, whose signs and symptoms may be much more severe. People with poorly controlled diabetes, those taking steroids (especially long-term), as well as individuals who wear dentures have a higher risk of developing oral thrush with more severe symptoms.

What are the signs and symptoms of oral thrush?
A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor detect. For example, pain may be a symptom while a rash may be a sign.
Oral thrush in adults generally appears as thick, white or creamy-coloured deposits (spots) on the mucous membrane of the mouth (wet parts inside of the mouth). The mucosa (mucous membrane) may appear swollen and slightly red. 
If the creamy or white-coloured deposits are scraped, bleeding may occur.
The white spots may join together to form larger ones, also known as plaques; which may then take on a grayish or yellowish colour.
Occasionally the affected area simply becomes red and sore, with no detectable white spots.
Individuals who wear dentures may have areas that are constantly red and swollen under a denture. Poor oral hygiene, or not taking the dentures out before going to sleep may increase the risk.

What are the causes of oral thrush?
Adult oral thrush is more likely to become a problem for the following groups of people:
1. People who wear dentures – especially if they are not kept clean, do not fit properly, or are not taken out before going to sleep.
2. Antibiotics – people who are on antibiotics have a higher risk of developing oral thrush. Antibiotics may destroy the bacteria that prevent the Candida from reproducing out of control.
3. Excessive mouthwash use – individuals who overuse antibacterial mouthwashes may also destroy bacteria which keep Candida at bay, thus increasing the risk of developing oral thrush.
4. Steroid medication – long-term use of steroid medication can increase the risk of oral thrush.
5. Other therapies – some medications, chemotherapies and radiotherapies may cause dry mouth. Dry mouth increases the likelihood of oral thrush developing.
6. Weakened immune system – people with weakened immune systems are more likely to develop oral thrush.
7. Diabetes – people with diabetes, especially if it is poorly controlled, are more likely to have oral thrush.

How is oral thrush diagnosed?
1.      In the vast majority of cases the doctor can diagnose oral thrush by looking into the patient’s mouth and asking some questions about symptoms.
The doctor may scrape some tissue from the inside of the mouth for analysis.
If the doctor believes the oral thrush is being caused by a medication, or some other underlying cause, that cause must be dealt with. Treatments in such cases depend on the underlying cause.

What is the treatment for oral thrush?
1.      Anti-thrush drugs, such as nystatin, amphotericin or miconazole in the form of drops, gel or lozenges. The patient may alternatively be prescribed a topical oral suspension which is washed around the mouth and then swallowed.
Oral or intravenously administered anti-fungals may be the choice for patients with weakened immune systems.