Q. Our son has a bad ulcer on his tongue and won't eat because it hurts too much. How can we help him feel better?
A. Ulcers in the mouth are pretty common in childhood and are usually caused by viruses such as herpes or the Coxsackie virus. They're typically gray or yellow with a red rim and may develop on the gums, the tongue, or the lining of the cheeks. They can occur alone or along with an illness that also includes fever, rash, cold symptoms, vomiting, or diarrhea.
Ulcers go away without treatment, and usually feel better within a week (although they may take longer to completely clear up). The biggest risk to a child is dehydration, if the pain stops him from drinking (this is most common in infants and toddlers). While it's okay if your child doesn't want to eat for a couple of days—he will when he feels better, and not eating is sometimes how the body conserves energy to help fight off the virus—he must drink. Stay away from anything acidic, though, such as orange juice or lemonade, which can sting. Cold liquids often go down better than hot; Popsicles may be a good choice since the iciness can ease discomfort (and kids feel like they're getting a treat). When he's ready to eat, avoid salty or spicy foods; they also sting. For starters, try things like ice cream, Jell-O or pudding.
I often prescribe a mouthwash for kids with painful mouth ulcers (your pharmacist will mix it; it typically contains a one-to-one ratio of Benadryl and Maalox or Kaopectate). This coats the sores so it doesn't hurt so much when they drink. Older kids can swish the mixture around their mouth and spit it out; littler ones can have it gently painted on the ulcers with a cotton swab.
If he truly won't take anything by mouth, call your doctor (you should also call if he has a fever higher than 102°F, if he's lethargic, if he has decreased urine output, or if an ulcer lasts for more than two weeks). In those cases, sometimes a stronger version of the mouthwash that includes an anesthetic may be prescribed. In rare cases, children who flat-out refuse to drink may need to be hospitalized to get intravenous fluids while their ulcers heal.