Dr. Keith Roach

DEAR DR. ROACH: Have you ever heard of “fibromuscular dysplasia”? My mom was diagnosed with this blood disorder and understands that there is no known medical procedure to treat it. She claims this is a blood disease that is affecting her kidneys, and she had a stent placed near the opening of her kidney to relieve any blockage.
Can you please provide me with more information on fibromuscular dysplasia and what is recommended for this disorder? — J.S.
ANSWER: FMD, or fibromuscular dysplasia, is rare (about 12 people per 100,000, 90% of which are female), but by no means unheard of. The average age of diagnosis is 52, but it can occur in children, often with a delay in diagnosis.
While your mother is right that it affects the kidneys, it isn’t a blood disorder at all. It’s a blockage of the arteries, most commonly one, or both, of the renal arteries that provide blood to the kidneys or the carotid arteries that supply blood to the brain. The blockage is not from cholesterol plaque; it’s from the fibrous and muscular tissue within the wall of the artery that blocks the artery and restricts flow. Poor blood flow can damage the kidney.
For FMD of the kidneys, blockage of the blood vessels means the kidneys sense low blood pressure, even when the blood pressure in most of the body is normal. The kidneys respond by secreting a substance, renin, which starts a cascade (the renin-angiotensin system) that causes the blood pressure to go up.
There are three treatments: medications to counter the activation of the renin-angiotensin system; angioplasty and stenting of the blocked renal arteries; and surgery, usually with a bypass graft. Most people who have angioplasty or surgery still continue to need medications. Only 31% have good blood pressure control without medicines, although most people who undergo a procedure do have better blood pressure control and require fewer medicines.
A procedure is indicated for those who don’t have good blood pressure control or who have progressive kidney disease despite medicines. When the diagnosis is found in children or young adults, the cure rate is higher, so a procedure may be effective in preventing the need for lifelong medications.
People with FMD of the kidneys, like your mother, should get an evaluation of the rest of her blood supply to determine whether any other blood vessels are affected. People with FMD should be on aspirin, unless there is a good reason not to use it.
DEAR DR. ROACH: I am an 83-year-old man on dialysis, who is experiencing tremendous itching on my torso all the way to my head. I’ve never had this problem before, and I am totally bewildered by this constant itching for the past two weeks. I try to ignore it, but that’s almost impossible. What do you think the problem may be, and is there an effective solution? — L.L.M.
ANSWER: Itching (pruritus) in people with kidney disease who are on dialysis is very common, and your kidney specialist will know a great deal more than I do about it. However, severe itching most commonly occurs when people aren’t getting enough dialysis, so an increase in the time of dialysis may resolve your problem.
The parathyroid gland helps regulate calcium and phosphate, so these need to be checked. Sometimes the parathyroid glands start making too much parathyroid hormone in dialysis patients. Emollients (skin creams and lotions that increase hydration of the skin) are also a standard treatment, but your next stop is a visit with your nephrologist.
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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.
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