Oral Thrush

A small amount of Candida normally lives in the mouth. Thrush develops when the fungus grows too much, which can happen when immunity is weak or antibiotics reduce the bacteria that usually keep it in check.

Thrush may clear with treatment, but it can return when the immune system is weak. In that setting, Candida can spread beyond the mouth and cause a serious infection.

Long-term antibiotics, steroid asthma inhalers, chemotherapy, high blood sugar, immune-weakening medicines and dentures that do not fit well are among the factors linked with thrush. Babies, older people and people in poor health are also more likely to develop it.

The characteristic pattern is white, velvety mouth or tongue sores, sometimes with bleeding after brushing or scraping. Cracks at the mouth corners, a sore tongue and pain on swallowing add useful clues.

Antifungal medicine can cure oral thrush. Nystatin is a liquid medicine held in the mouth for as long as possible before swallowing, so it stays in contact with the affected area.

Oral thrush is treated with antifungal medicine rather than a filling, crown or other dental restoration. Nystatin is one antifungal supplied as a liquid for use in the mouth.

Candida can cause a serious body-wide infection when immunity is weakened. The infection may affect the brain, oesophagus, eyes, heart or joints, rather than remaining confined to the mouth.

Thrush is less likely when the factors that let Candida multiply are addressed. Long antibiotic courses, asthma inhalers and cancer treatment are recognised circumstances in which the fungus can grow more than usual.