DEAR DR. DONOHUE: Since my 26-year-old son was a child, he has suffered with numerous canker sores. He has tried every over-the-counter product and has asked every doctor and dentist he has seen for advice. Nothing works for him. Is it possible to culture these sores and determine the cause? – S.B.

Just about everyone has had at least one canker sore. Most heal on their own in a week to 10 days even without treatment, but it’s a miserable time while they’re present.

Many causes have been advanced. Some feel that mouth bacteria, which have been cultured, are responsible. Others propose that canker sores are the result of an immune attack on the mouth membranes. Food allergies, hormonal changes and a genetic predisposition also have been advanced as possible causes. In a few instances, canker sores are seen in conjunction with other illnesses, like celiac disease, Crohn’s disease and Behcet’s disease.

There are some things your son can do to lessen the frequency of outbreaks. He has to protect his mouth from any injury, which means his toothbrush should be soft, he shouldn’t eat hard, crunchy foods like toast, and he should stay away from acidic foods and drinks. Readers write in to say that when they have changed toothpastes from ones containing sodium lauryl sulfate to ones without that ingredient, their canker sores left. Others proclaim the efficacy of L-lysine. Milk of magnesia, Kaopectate and liquid Benadryl can be swished around in the mouth and then spit out, and they have helped canker sore victims. A new product, Cankermelts, is an adhesive patch containing licorice extract and has been recently featured in the dental literature as being an effective treatment. The patch dissolves. The manufacturer is Orahealth.

Cortisone drugs incorporated into gels and applied to the sore have had good reviews. Some examples are Lidex, Diprolene and Temovate. Kenalog in orabase is a pastelike cortisone product that sticks to the sores. Aphthasol oral paste is another, somewhat newer treatment that often brings relief.

DEAR DR. DONOHUE: About nine months ago I developed canker sores. They go away, but always come back. My doctor and dentist prescribed antibiotics, which helped some for a brief time. I then saw an oral surgeon, who diagnosed this as Sutton’s disease. He prescribed dexamethasone liquid as a mouth rinse. It gives a measure of relief, but if I am off this for four days, the sores come back.

What can you tell me about Sutton’s disease? How does one get it? – C.E.

Most people – 80 percent to 85 percent – with canker sores have minor canker sores. They’re minor because they’re smaller than 1 cm (.4 inch) in diameter and relatively shallow. Major canker sores are larger and deeper, and they recur more frequently. Major canker sores are also known as Sutton’s disease. The proposed causes are the same as for minor canker sores.

Your dexamethasone mouth rinse is one of the cortisone drugs used to control canker sores. You might want to try one of the others I mentioned to S.B. or the licorice extract patch. If the outbreaks are severe and interfering with eating, thalidomide has been successful in people plagued with unrelenting attacks. You might remember thalidomide as the drug that caused malformation in so many babies some time ago. It cannot be given to pregnant women or women intending to become pregnant. It has to be monitored with close observation.

Readers wanting information on fibroids can obtain the pamphlet on that topic by writing: Dr. Donohue – No. 1106, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: Are you ever going to get back to me about the numbing sensation around my ankles? I have had tests and have been to three different doctors. My circulation is good, and I don’t have any nerve damage. What’s causing this? – K.R.

ANSWER: I’m sorry but I don’t have a clue.

DEAR DR. DONOHUE: My nephew, who is 11 years old, is knock-kneed. It doesn’t faze him in the least. He’s a very active boy and into all sports. In fact, he’s a very fast runner. Should something be done for this? If so, what? My sister says she has had him examined by a doctor. – D.M.

With knock-knees, the knees touch or are close to touching when the person stands with feet apart. Knock-knees are common at the ages of 3 and 4. Then leg bones eventually straighten, and the knees become aligned properly. If knock-knees persist past these early years, a doctor should be consulted. Sometimes braces can remedy the deviation, and sometimes surgery is necessary.

Apparently your nephew’s knees are not turned to such a degree that any interference is required.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from

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