When a child who usually eats well suddenly refuses food and drink, drools, and fusses, parents often check inside the mouth. White or red sores there may be stomatitis. Most cases improve within a few days to 1-2 weeks, but the main thing to watch is whether pain is keeping your child from drinking enough.
Why It Happens
Seattle Children’s notes that canker sores are the main cause of one or two mouth ulcers after age 5, while hand-foot-and-mouth disease is the most common cause of multiple ulcers at once. Other causes include herpangina, a viral infection with small blisters at the back of the mouth and throat, and first-time herpes simplex infection, which can cause painful, swollen gums and sores called gingivostomatitis. A bitten cheek, a scrape from crunchy food, or a newly started medicine can also trigger sores.
How It Looks at Different Ages and Stages
Herpangina usually affects children from about age 2 to 9 and tends to come with fever and blisters on the roof of the mouth and near the throat. A young child with a first herpes infection may have swollen, easily bleeding gums, heavy drooling, and fever. In contrast, one or two small, painful sores on the inner cheek or tongue without fever are more typical in school-age children, and such small sores often fade on their own within 1-2 weeks.
Home Care
The goal is to keep your child eating and drinking. Cold foods such as cold milk, yogurt, smoothies, or ice cream may soothe pain. Acidic fruit, salty snacks, and rough or crunchy foods can irritate the sores, so it is often better to avoid them for a while. Offer small, frequent sips by straw or small spoon, and encourage water, milk, or oral electrolyte drinks. If pain or fever is significant, ask your doctor or pharmacist about an age- and weight-appropriate pain reliever. Brush with a soft toothbrush and avoid rubbing directly on the sores.
Common Parent Misconceptions
Some parents think vitamins are needed to heal mouth sores, but most childhood cases improve with time whatever the cause, and easing pain and keeping fluids up matter most. Forcing food on a child in pain can increase refusal, so for a few days it may be more helpful to focus on drinking than on eating. Not all mouth sores are the same illness either; hand-foot-and-mouth disease and herpes infections can spread to other children, so decisions about daycare are best based on fever and how your child looks.
Signs That Need Medical Care
Seattle Children’s advises calling a doctor right away if dehydration is suspected, such as no urine for more than 8 hours, dark urine, a very dry mouth, or no tears when crying. Contact a doctor within 24 hours if there are 4 or more sores, fever, a swollen face, or if sores began after starting a medicine. If a headache or neck pain does not improve with pain relievers, or your child is hard to wake or unusually sleepy, go to the emergency room right away, because the viruses that cause herpangina can rarely cause meningitis. This information isn’t a diagnostic tool and doesn’t replace advice from a medical professional.