The most likely cause of your baby's white tongue bumps and white patches inside the mouth is the medical condition called thrush.
Thrush is an overgrowth of the yeast germ, Candida , producing white patches inside the mouth. It is most commonly seen in babies but may occur in anyone who has been on antibiotics for a long time.
Thrush can be distinguished from the white coating of milk left behind after feedings by gentle washing of the white patches. Thrush is firmly stuck against the mouth, and if you manage to get some off, the surface left behind is swollen and red. If the white patches are easily removed, then it probably is not thrush.
Each of us has yeast in our mouth, as these little germs live there in harmony with normal mouth bacteria. Babies usually obtain both yeast and bacteria from their mother’s birth canal. In some cases the yeast growth overtakes bacterial growth before the body develops a balance between the two, and thrush develops.
Thrush is treated either by the antifungal prescription nystatin oral suspension or gentian violet, available over the counter. A 1% solution of gentian violet is applied with a cotton swab to the white patches 1-3 times a day. The major problem with gentian violet is that it is messy and stains everything purple including clothing, nipples, the carpet, and the skin. In fact, articles of clothing can be permanently stained. The nystatin is more convenient but more expensive. It is given four times a day and placed on each side of the mouth. If the thrush isn’t responding, rub the nystatin after meals directly on the affected areas with a gauze wrapped around your finger. Breast feeding moms should apply nystatin to their breasts as well. Some physicians will not even treat thrush since it will eventually go away and most babies do not seem to have any discomfort from it.
If thrush is present, carefully wash the nipples and pacifiers and anything else that goes into baby’s mouth. It is a good idea to store bottles, nipples, and pacifiers in the refrigerator -- the yeast do not like a cold environment. By the way, normal children and adults do not get thrush since they develop an immunity to the overgrowth of the yeast germ.