If your baby is teething and has blisters on their tongue, it could be caused by one of several conditions. Fever or a skin rash may accompany blisters in a baby's mouth if they have a virus. Blisters can also be the result of biting the tongue or salivary gland blockage.
The blisters may be painless or painful. Some blisters may rupture and form ulcers, or shallow wounds in the mouth. This process can be painful. Other blisters, which are usually painless, can persist and have clear fluid inside of them. If a virus caused the blisters, your child may have a fever, sore throat, irritability, itchy skin, fatigue or poor feeding.
A virus that commonly affects infants and children named the Coxsackie Virus causes Hand, Food and Mouth Disease (HFMD). HFMD is very infectious and causes fever, blisters in the mouth and may be associated with a skin rash. The illness usually begins with the baby developing fever, sore throat and being very tired. They may refuse even their favorite juices and drinks because of sore throat. One to two days after the onset of fever, painful sores develop in the mouth. They start out as red spots on the tongue, gums and cheeks that blister and turn into ulcers. In that same time period, a skin rash with flat or raised red spots and blisters may appear on the palms of and soles of the feet. Some babies will have the rash on their buttocks and genitalia.
Smaller painful bumps on the tongue could be inflamed papillae, the taste buds on your baby's tongue. Sometimes they are inflamed due to feeding your baby something that is too hot -- for example, over heated formula -- or from biting the tongue.
Fluid-filled blisters under the tongue may be present which are painless. These are called mucocele cysts and are formed from sucking the mouth tissue between the teeth or blockage of a salivary gland.
If your baby has Hand, Foot and Mouth Disease, it is caused by a virus, which will run its course without treatment. Avoid giving your baby anything that will irritate the blisters. Instead, give your child ice cream and popsicles. There is no specific treatment for Hand, Foot and Mouth Disease, so if your child has fever or pain, you should give acetaminophen or ibuprofen according to the directions on the box. Do not give your baby aspirin. The virus is spread through infected saliva, stool, blister fluid and throat secretions so be sure to wash your hands after contact with your baby and any changing surfaces. Disinfect surfaces and toys with soap and water, then a disinfectant solution, such as 1 tbsp. of chlorine bleach to 4 cups of water.
Inflamed papillae and mucocele cysts will heal on their own without treatment. If your baby has pain from inflamed papillae, try to keep them comfortable with things like ice cream or popsicles until they feel better. Use acetaminophen or ibuprofen for pain if needed.
If your teething baby has blisters on their tongue, it could be from a viral illness, which is highly contagious, or a condition that will heal on its own. Be sure to look for any other associated symptoms such as fever or skin rash to determine if you should be worried about spreading an infection to other family members.