What are the signs of a canker sore?

What the sore itself usually looks like

A canker sore is generally small, often under half an inch across, with a defined round or oval shape rather than a ragged patch. The center tends to look pale white or yellowish, surrounded by a ring of redness where the tissue is irritated. It sits on the soft tissue inside the mouth, the inner cheek, the inner lip, along the gumline, or the tongue, never on the outer lip or skin around the mouth.

Most children get just one, or maybe two or three at once, rather than a mouthful of sores. That pattern matters, because a single mouth sore reads very differently from several appearing together, which is covered further down.

Signs beyond the sore itself, especially in younger kids

A child old enough to describe pain will usually just say a spot in their mouth hurts, especially when eating something salty, acidic, or crunchy that rubs against it. A younger child who cannot describe it as clearly might show it differently instead: pulling away from certain foods without explanation, drooling a bit more than usual, pointing at a cheek, or general fussiness around mealtimes that does not have an obvious cause.

A canker sore on its own typically does not come with a fever. If a fever shows up alongside mouth sores, that points toward something else going on, which the next section covers.

It depends on the child, and often no cause is ever identified

Mainstream sources describe a range of possible contributors to a canker sore: a minor bite or scrape from a toothbrush or a piece of food, certain acidic or spicy foods, ordinary stress, or simply a family tendency toward getting them. Rarely does any single cause explain a specific sore, and plenty show up with nothing obvious behind them at all.

Some children seem prone to getting one every so often, while others rarely get one in their whole childhood. Neither pattern is something to read too much into on its own. If sores are showing up often enough to worry you, that is worth mentioning to your pediatric dentist rather than trying to track down a cause yourself.

When a mouth sore is worth a call rather than just watching

Most canker sores heal on their own within one to two weeks and are more of an annoyance than a medical concern. A few signs point toward calling instead of waiting it out:

• Several sores appearing at once, rather than just one or two
• A sore that is still there well past the two week mark
• A fever alongside the mouth sores
• Your child refusing to drink and showing signs of not keeping up with fluids
• A sore that shows up on the lip itself rather than inside the mouth, which points toward a cold sore instead

Noticing one of these is a reason to call, not a diagnosis on its own. Either office can take a look: (239) 482-2722.