For people with lowered immunity, such as from HIV or cancer, however, thrush can be more serious. Untreated oral thrush can lead to more-serious systemic candida infections.
Oral thrush can also lead to a condition
called burning mouth syndrome, which can have symptoms of a painful burning
sensation, mouth dryness, soreness, tingling or numbness throughout the mouth
and tongue, and sometimes an abnormal bitter or metallic taste in the mouth.
In severe cases of thrush, the esophagus,
which leads down to the stomach, may also be involved. This will cause pain
with swallowing. If someone has a weakened immune system (HIV/AIDS, cancer,
chemotherapy, etc.), the Candida fungus can spread to other parts of the body
and cause a systemic infection. If a person has signs or symptoms of thrush and
develops a fever, shaking or chills, or difficulty swallowing, contact a doctor
immediately.
