DEAR DR. DONOHUE: I have had ulcers since 1943. Since then I have had many bouts with ulcers. In 1995, a biopsy identified H. pylori, and antibiotics were given. Is it possible that I was infected by inhalation of H. pylori because I didn’t wear a mask while treating soldiers during World War II? I was and am a dentist. – L.G.

ANSWER: A bit of backpedaling is necessary for readers to understand your question.

Twenty years ago, two Australian doctors made a remarkable discovery that radically changed ulcer treatment. They found that a bacterium, Helicobacter (HEEL-ee-coe-BACK-tur) pylori (pie-LOR-ee) played a role in causing ulcers and, quite importantly, in ulcer recurrence. Since their discovery, antibiotics have become standard treatment of ulcers in addition to drugs that control stomach acid production. Eradication of H. pylori makes a return of ulcers most unusual.

In developed countries, about 40 percent of the population harbor this germ in their stomachs. In developing countries close to 90 percent carry the germ in their stomachs.

How do people get this germ? The most likely route is through the mouth. Food or drink contaminated with the germ from someone carrying it serves as the route of transmission. Airborne transmission is not considered a probable mode of infection. Wearing a mask while working on soldiers’ teeth, gums and mouths was not and is not necessary for this purpose.

There are some puzzling aspects to the H. pylori story. If 40 percent of North Americans carry the germ, how come only 10 percent of men and 4 percent of women come down with ulcers during their lives? There must be other factors at work. Curtailing stomach acid production, therefore, remains an essential part of ulcer treatment.

DEAR DR. DONOHUE: My right earlobe developed an itchy feeling and then a sore. The dermatologist told me I was allergic to nickel. I wear earrings and do not feel fully dressed unless I have them on. The doctor said that gold or silver earrings also contain nickel. Is there a way to correct this problem? I am 83 and have worn earrings since I was a teenager. – V.H.

ANSWER: Skin sensitivity to nickel is similar to skin sensitivity to poison ivy. Both can cause an outbreak of an itchy rash. That is called contact dermatitis. Nickel is so widely used in jewelry, including wristwatches, that nickel-caused rashes are quite common.

The surest way to avoid a nickel-caused skin rash is to avoid anything that has nickel in it. Gold of 18-to-24-karat purity is less likely to provoke a rash. So is stainless steel. Don’t buy any jewelry unless you have it on good information that it can be worn without causing a skin rash.

For cheaper jewelry, you can coat the clasp and any metal that comes in contact with the skin with clear nail polish. The clear nail polish wears off rapidly, so it’s necessary to coat the jewelry often.

I understand plastic jewelry is available.

Talk with neighborhood jewelers. See if any coats jewelry with polyurethane. It provides three months of protection. One brand name for polyurethane is Flecto.

DEAR DR. DONOHUE: My 24-year-old grandson had two fatty tumors removed from his right side two years ago. Two more have appeared at two new sites. Can this run in families? How can one prevent them from developing in the future? Does diet play a role? – P.O.

ANSWER: Those fatty tumors are lipomas. “Tumor” always raises the hair on people’s necks. They take it to mean cancer. Lipomas are almost never cancer and almost never turn into cancer. They are soft, rubbery, round growths of fat cells that lie beneath the skin. They don’t usually hurt. They can be surgically removed or removed with liposuction if they cause any trouble. For the ordinary lipoma, heredity is not a big factor. Nothing can be done for prevention. Diet does not play a role in their appearance.

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.