DEAR DR. DONOHUE: My 20-year-old granddaughter has Crohn’s disease. I am very concerned because I know nothing about this illness. Would you be kind enough to let me know if it can be treated and cured? – E.R.

ANSWER: Crohn’s disease is one of two inflammatory bowel diseases. The other is ulcerative colitis. Although they share some common features, such as inflammation of the digestive tract, each has distinctive features. Crohn’s can affect the entire digestive tract from mouth to anus. Ulcerative colitis strikes only the colon. The ulcers of Crohn’s disease are deep. Those of ulcerative colitis are shallow.

Crohn’s main symptom is recurrent bouts of pain, mostly on the lower right side of the abdomen. The pain comes in waves and is usually relieved by a bowel movement. Diarrhea is common, as is weight loss.

There are two peak ages when Crohn’s most frequently makes its appearance: the ages between 15 and 30 and between 60 and 80.

Crohn’s might be an inappropriate response by the body to the normal bacterial population that lives in all digestive tracts. A misbehaving immune system makes its contribution to the illness also.

Definitely, Crohn’s can be treated. At present, “cure” is too strong a word to use, but control is possible for most patients. The same medicines given for ulcerative colitis are used for Crohn’s disease – sulfasalazine, Asacol and Pentasa. When the illness is out of control, cortisone drugs can usually calm the inflamed, ulcerated digestive tract. Medicines directed at reining in the errant immune system also come into play. Two examples are azathioprine and 6-mercaptopurine. The newest Crohn’s medicine is Remicade.

With treatment, most Crohn’s patients live a long, productive and active life.

Your granddaughter (and all Crohn’s patients) should contact the Crohn’s and Colitis Foundation. Its Web site is www.ccfa.org, and its toll-free American number is 1-800-932-2423. Canadians can called their foundation at 1-800-387-1479.

DEAR DR. DONOHUE: More than two years ago, I had a colonoscopy and was diagnosed with Crohn’s disease. The doctor saw ulcerations at the end of my small intestine.

By accident I forgot my Asacol when I was away for a few days, and had no trouble. As a matter of fact, I never had any problems even before I was diagnosed. So far I have been off medicine for two months, and still no problems. My family doctor says to stay off the medicine and see what happens. I wonder about getting a second opinion and why the diagnosis was made. I have been turned down for insurance by two companies and am frustrated that this diagnosis is on my medical record. Do you have an opinion about this? – G.L.

ANSWER: Crohn’s disease usually produces symptoms of right lower abdominal pain, rectal bleeding, diarrhea, weight loss and night sweats. I’m surprised you have none and never did. Most patients do.

A barium enema of your small intestine might remove doubts about the diagnosis. In addition, many Crohn’s patients have an antibody in their blood called ASCA. When present, it furnishes more evidence in confirmation of the diagnosis.

I happen to like your idea better than mine. I agree that a second opinion is the sane approach for you to take.

DEAR DR. DONOHUE: I am in my late teens and concerned about my skin. I have stretch marks from an unfortunate and dramatic weight gain. I am doing well at losing the weight (without surgery or pills), but my battle scars are worse than my mom’s and my doctor’s, both of whom had kids. I wonder if there is anything better to do than apply vitamin E. Is there anything you can suggest for eliminating stretch marks beside expensive professional procedures? – K.

ANSWER: Stretch marks are long, thin scars that form when skin is stretched beyond its elastic properties. Obesity, huge muscles, pregnancy and the rapid growth that occurs during puberty leave many with stretch marks. Early on, they are raised and purple and quite noticeable. With the passage of time, they flatten and lose their color and are not so noticeable. Retin-A, an acne medicine, might make them less obvious. Mother Nature is on your side if you can be patient.

DEAR DR. DONOHUE: I am an 83-year-old man, and I keep a very clean house. I came down with itching and redness of my skin, and the doctor said I had scabies. I was given a cream, but it keeps coming back. Help me understand this. – Anon.

ANSWER: The female scabies mite burrows into the skin to lay her eggs. The mite is very small, and you need a strong lens to see it. You can, however, recognize the burrows. They’re dark, wavy, threadlike lines on reddened skin, and they are found between the fingers, on the wrists, near the armpits, under the belt line, on the upper thighs or around the ankles.

The itch of scabies is ferocious, and it gets worse at night.

One application of permethrin cream can usually eliminate the mite. Some doctors have patients apply it again in one week to assure that the mites are eradicated.

The itch of scabies can last for weeks after the mite is gone, and many people believe they are still infected. They are not. The itch comes from an allergic reaction, and it lingers and lingers. This might be what’s happening to you. Antihistamines like Benadryl can usually keep it under wraps, as can calamine lotion.

If you think you are being reinfected, get a confirmation of that. The confirmation is obtained through skin scrapings that are examined with a microscope to find the mite, its eggs or its droppings. If that evidence is not found, it is not likely that your skin problem is a recurrence of scabies.

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.