DEAR DR. DONOHUE: My 12-year-old granddaughter has severe ulcerative colitis. We have been told that blood tests indicate that it’s genetic. Since no one on either side of her family has the disease, this puzzles us. How will it affect her future? – B.G.

ANSWER: With ulcerative colitis, the surface of the colon is studded with raw sores – ulcers. It can strike in childhood. About 18 percent of ulcerative colitis patients are younger than 18. The salient signs of ulcerative colitis are crampy abdominal pain with diarrhea, which is often bloody.

Genes do play a role in this illness. Up to 30 percent of patients have a family member who also has it, but genes are not the only factor involved in its genesis. If one identical twin has the illness, the chances that the other twin will get it are high, but far from 100 percent. Identical twins have the same genes. If genes were the only influence, both identical twins would come down with it. Other, as-yet-undiscovered pieces of the puzzle eventually will be found.

Your granddaughter lives in a time and place with many control medicines for ulcerative colitis, and she can look forward to a full, active life with a career in any field she chooses. She can play athletics if she wishes to. Ulcerative colitis is an illness in which there are times of flares interspersed with periods when the illness is quiet. During flare episodes, she’ll have to curtail activity, but those episodes should not dominate her life.

At her young age, growth and eventual puberty require great attention. A dietitian would be a great value to her and her family in planning meals that maximize nutrition.

Your granddaughter and her family will be greatly benefited by introducing themselves to the Crohn’s & Colitis Foundation of America, which provides information and timely tips for handling this illness. The foundation can be reached at 800-932-2423 and can be found on the Internet at www.ccfa.org. Canadians can contact the Crohn’s & Colitis Foundation of Canada at 800-387-1479 and at www.ccfc.ca.

DEAR DR. DONOHUE: I find that I cannot take the cold. When cold air hits me, it feels as though I have been in a large thicket of stinging nettles. My skin turns bright red. I can’t have cold water on my hands. Winter is a real concern. Do you have any idea what this is? – B.H.

ANSWER: I can suggest three rare conditions that it could be.

One is familial cold autoinflammatory syndrome. Cold exposure in people with it triggers a red rash that stings. Often, people have a fever and joint pain. The reaction usually occurs an hour or two after exposure, and frequently other family members suffer from it.

Cold urticaria is a slightly more common condition. Affected people, when placed in a cold environment, experience itchy, swollen, red skin with hives. Many times the reaction occurs when these people start to rewarm.

A third possibility is a reaction to cold in people whose blood contains a protein that responds peculiarly when exposed to cold. The skin becomes red and itchy or painful.

A trip to a dermatologist or allergist will prove or disprove these suggestions.

DEAR DR. DONOHUE: Both my total cholesterol and LDL cholesterol numbers are high. I am a 53-year-old male and weigh 144 pounds. My doctor wants me to take Zetia and a statin drug. Do you recommend that? How often must I have blood tests when taking these medicines? – S.M.

ANSWER: Zetia (ezetimibe) blocks cholesterol absorption in the digestive tract. Statin drugs stop the liver’s production of cholesterol, which is the source of most of our blood cholesterol. The two drugs often are combined, since they work at different sites. There’s a pill that contains both – Vytorin.

Zetia has few side effects, and blood tests are not routinely done when taking it. Statin drugs, in a very few instances, can cause liver and muscle damage. The general recommendation for these drugs is to have a liver-function test done before starting them and again after 12 weeks of therapy. Tests are done periodically after that.

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 www.rbmamall.com