DEAR DR. ROACH: Around two years ago, I had an L4/L5 herniated disc that caused a sciatic nerve problem. My doctors tried prescription medication (including medicine to act on the nerves), two lumbar injections and physical therapy. I also tried a chiropractor and acupuncture.

After all of the above steps, my back pain has basically gone away, with the exception of numbness/tingling in my right foot. This numbness/tingling varies in intensity from light to strong. I have been reading about spinal decompression, but at this point, I am not sure what else to do. Do you have any recommendations?

— M.B.

ANSWER: I do not recommend spinal surgery for numbness and tingling. Although most people do well with surgery, I have seen enough people have bad outcomes after surgery (including weakness and intractable pain) that I recommend surgery only with pain so severe that it can’t be effectively treated; with weakness (immediately, if the weakness is progressing); or with symptoms affecting the bladder or bowel. All of these only after optimal nonsurgical treatment for at least six weeks).

Virtually all spine surgeons I have worked with are very cautious and conservative about recommending surgery (that is partially because I tend to refer to surgeons who do not easily recommend operating).

Most people will find that the numbness and tingling go away, but two years is a long period of time. I understand why you might be frustrated.

DEAR DR. ROACH: I have brown spots over the top half of my body. The doctor says they are seborrheic keratoses and are harmless and not precancerous. Why do I have them? How can I stop them? Some of them itch.

— G.B.G.

ANSWER: Seborrheic keratoses are benign skin lesions, usually easily identifiable due to their “stuck-on” appearance and slight bumpiness. It’s not really clear why people get them. Some theorize they are due to sun exposure, but the evidence for that isn’t as clear as it is for other kinds of skin lesions. If necessary, a dermatologist can take a biopsy to make 100 percent sure they aren’t something more serious.

If a lesion is symptomatic (in addition to itching, sometimes they can bleed or be painful), or if it is located in a cosmetically important place, they can be removed. Liquid nitrogen, shaving off with a scalpel, and laser treatments are among the methods dermatologists use to remove these.

I don’t know of any way to prevent them from occurring.

DEAR DR. ROACH: What causes fungus between fatty folds of skin? A medical assistant says that if I lower my sugar, that will help. She said fungus likes sugar.

— B.M.G.

ANSWER: I think you are talking about intertrigo, a type of skin inflammation in skin folds, such as the groin, armpit and below the breasts that is often associated with infection with the fungus Candida, a type of yeast. People with diabetes are more at risk for this condition, but other conditions, such as HIV, excess sweating and incontinence also can predispose a person to this condition. When areas of moist skin rub against each other, it can take off the top protective layer of skin and cause inflammation. Yeast and bacteria can then come in and further worsen the inflammation.

Treatment starts with reducing moisture and friction. Daily cleansing with air drying (a hair dryer on the cool setting is good) followed by drying powders may be enough for many. Antifungal creams usually are added, however.
Excellent control of diabetes is good for many reasons, including helping intertrigo heal faster.

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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.