Cold Sores vs. Canker Sores: How to Get Rid of Mouth Sores

There are two very different kinds of common mouth sores: cold sores, or herpetic stomatitis, and canker sores, or aphthous stomatitis. Here's how to tell the difference and help them heal quickly.

boy with open mouth
Photo: TY Lim/Shutterstock

No one likes a mouth sore -- especially parents when it's their kid who is the one suffering. Knowing how to help your child heal starts by knowing more about the two most common types of mouth sores. Why? Because treatment totally depends on which one she's suffering from.

Cold sores are caused by the herpes virus, and canker sores are not, but sometimes they can be difficult to tell apart, explains Alan Greene, MD, FAAP. With herpes sores, even though the first ones can be on the lips or in the mouth, the recurrent ones tend to be only on the lips. So if the recurrent ones also occur inside, on the gums and on the roof of the mouth, then canker sores are generally the problem.

Read on to determine if you have a little one suffering from a cold sore or a canker sore, and learn how to treat it.

What is a canker sore?

Canker sores, or mouth ulcers, are open sores on the inside of the cheeks, lips, or tongue. Viruses cause some canker sources, most often the chicken pox and the coxsackie viruses, but often the cause is unknown. Most of these sores are not contagious, but sores caused by the herpes virus, called cold sores, which develop on the outside of the mouth around the lips, are very contagious and easily spread.

Canker Sore Causes

Some people get canker sores after eating certain foods; others get them after using toothpaste with foaming ingredients. Sometimes ulcers appear at the site of minor trauma in the mouth; for example, biting the inside of the cheek or scraping the cheek with a hard piece of food, such as a lollipop. They can occur at any age, although they are more common in older children, adolescents, and adults.

Canker Sore Symptoms

When canker sores occur, children complain of pain in the mouth, and one or more sores on the mouth?s mucus membranes are visible. They often have a grey, punched-out center and a white or yellow edge surrounded by redness. The sores bleed easily (when brushing the teeth) and usually last for several days. Occasionally, they may last for one to two weeks before disappearing. Viral infections that cause canker sores may also be accompanied by a fever.

How to Prevent a Canker Sore

Because most canker sores do not have a known cause, they cannot be prevented. If your child seems to get sores in the same spot inside the mouth, the sharp edge of a tooth could be the cause. If this is the case, have your child evaluated by a dentist.

How to Treat a Canker Sore

For the most part, canker sores are harmless and heal by themselves, but the pain can be severe. In rare cases, small children may refuse to drink and as a result become dehydrated. If your child has a canker sore, ask your doctor about relieving pain with acetaminophen (Children's Tylenol) or ibuprofen (Children's Advil). Your child should also avoid acidic, spicy, or salty foods or drinks, such as orange juice or tomato sauce. Some children experience relief when pressing an ice cube against the sore, and ice pops often help relieve pain and provide necessary fluids. You may need to use an anesthetic ointment or gel for a short period of time. If your child has cold sores caused by the herpes simplex virus, consult a doctor, who will determine whether it is appropriate to prescribe an antiviral medicine.

What is a cold sore?

Cold Sore Causes

Since cold sores are caused by the herpes virus, adults can infect a child with cold sores through direct contact from saliva through kissing.

Cold Sore Symptoms

Symptoms of cold sores include a high fever, difficulty swallowing, and general soreness in the mouth. A child may have ulcers on the lips and on the skin around the mouth, and the lymph nodes around the neck will be swollen. Unlike most viruses, the herpes virus stays in a person's body forever, and it gets reactivated throughout life. When this happens, there is a tingling or numb feeling around the mouth, followed by a blister that eventually bursts open and scabs over. Cold sores often reappear when the person has a cold or another infection, has too much exposure to sunlight, has stress, or is menstruating.

How to Prevent a Cold Sore

Parents should always wash their hands well before touching the child. This is especially important with newborns and children who have problems with their immune systems. If your child does have a cold sore, make sure that he does not rub the sore and then touch his eyes, as this could spread the virus and cause an infection.

How to Treat a Cold Sore

If your child has cold sores caused by the herpes simplex virus, consult a doctor, who will determine whether it is appropriate to prescribe an antiviral medicine.

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