Doc: Mystery seven-year itch could be shingles
Dear Dr. Roach: For seven years I have had an itch under my shoulder blade on my back. It stretches from the left side to the center. There is no rash or anything visible on the skin; it just itches all the time. Neither my physician nor my dermatologist has a remedy. My physician indicated that it might be shingles, but under the skin. It that were the case, where is the pain associated with shingles?
Dear J.C.: It is true that after an episode of shingles, some people have severe, prolonged itching. The fact that this is on a discrete area on one side does suggest that it might be itching related to a damaged nerve, and shingles certainly damages nerves. Some people with shingles have only mild pain, while others may have pain without a rash, but a rash and moderate to severe pain is the most common presentation, by far.
However, I think it’s much more likely that you may have the condition notalgia paresthetica, a condition of localized itching thought to be related to nerve compression in the upper back. There is no rash, apart from damage done where people scratch too much.
The most common treatment is topical capsaicin cream. Sometimes oral medications are used, and other treatments have included nerve stimulation (TENS) and nerve block.
Dear Dr. Roach: It will be two years in July that I had two metal plates put in my left leg at the ankle — one on each side of it, plus about 20 pins — due to an injury caused by being hit by a car. I believe they are made of titanium.
I was just recently injured by a shopping cart. My question is whether an MRI is safe for my back, which still bothers me. I have been told it is, but I would like your opinion, please.
Dear C.M.: If you are sure that the metal is titanium, then an MRI is safe. However, you don’t sound 100 percent sure, so what I’d recommend that you do is get a copy of the operative report from your surgery back in 2014. That should contain the exact description of the metal plates used, in order to determine whether it’s safe for use in an MRI scanner. Most plates used now are, but since the MRI can generate a great deal of heat, most MRI facilities will not perform the test without being sure.
Dr. Roach Writes: Recently, I wrote about a gentleman with pain down the back of his legs when driving for a prolonged period, and a surprisingly large number of readers wrote in to tell me to advise him to make sure he had removed his wallet from his rear pocket. Certainly, the wallet can act to press the sciatic nerve against the bony structures of the pelvis, causing pain and tingling sensations from the buttock down to the calf or foot. Apparently, this is far more common than I had realized. One gentleman called it “walletitis.” Another suggested a “walletectomy.” One reader (one of the few without a wallet) told me that changing the seat position solved the problem.
Email questions to ToYourGoodHealth@med.cornell.edu.