White, slightly raised areas in your mouth are common signs of thrush. It s an infection caused by the candida fungus, which is yeast. thrush [thrush] infection of the oral mucous membrane by the fungus Candida albicans; called also oral candidiasis. That is, oral candidiasis is a mycosis (yeast/fungal infection) of Candida species on the mucous membranes of the mouth.. Candida albicans is the most commonly implicated organism in this condition.C. They can also appear on the roof of your mouth… Thrush often appears in a baby’s mouth during the first few weeks or months of life. Oral candidiasis, also known as oral thrush among other names, is candidiasis that occurs in the mouth. It is characterized by white patches on a red, moist inflamed surface, occurring anywhere in the mouth, including the tongue, but usually on the inner cheeks, occasionally accompanied by pain and fever. 'Oral thrush, or oropharyngeal candidiasis, is a candida infection in the mouth and throat. If you notice a strange white rash inside your mouth, you may have a condition called thrush. Researchers aren’t sure why, but it could happen because a newborn has a … They re usually found on your tongue or inner cheeks.