Your health questions answered

Why is my leg hairy? Is my nerve trapped?

HAIR TODAY...

Q. I have had a full leg cast on for seven weeks and when it was taken off I found that the affected leg has acquired significantly increased hair growth. I am rather dismayed about this and would like to know why.

Although this phenomenon has not been discussed much in the medical literature, there is one theory to explain why the hair grows. The skin under the plaster cast is subjected to tiny amounts of friction as the cast moves. The friction is not enough to rub away hair, but it is enough to stimulate the hair follicles in the skin to produce new hairs. As the skin is subjected to its normal wear and tear, the excessive hair will gradually disappear.

BURNING HAND PAIN

Q. I have a constant and often quite severe burning pain in the back if my right hand, from the thumb to the middle of the hand and down to the wrist. I've been told that it's probably a problem with the radial nerve, and have been given various exercises to try to alleviate it but they haven't worked. An X-ray has shown obvious wear and tear to two vertebrae in my neck. Is there any cure for this?

The radial nerve runs down the arm from the shoulder to the thumb side of the hand, and the area of pain that you describe - on the back of the thumb and hand - is where the radial nerve ends up. But if the radial nerve is the culprit, I am surprised that you are suffering from pain, rather than from either numbness or weakness, which are much more common symptoms of radial nerve problems. Another possibility is that the nerve root called C6 is being irritated or pinched as it comes out of the spinal cord and passes through the neck. The "wear and tear" that you can see on your neck X-ray may mean that a bone spur has grown that is pressing on the C6 nerve root. Physiotherapy and exercises may help. But if the pain persists, I think it would be wise to have some further investigations - possibly a chest X-ray, an MRI scan of the neck to see which nerve is under pressure, or an electrical test to see if the nerve impulses are being properly transmitted. Very occasionally this type of pain can be caused by a growth or tumour in the armpit or at the top of the lung that is causing pressure on a nerve. Even diabetes can cause nerve pain, so a blood or urine test may be sensible.

Please send your questions and suggestions to A Question of Health, The Independent, Independent House, 191 Marsh Wall, London E14 9RS; fax 020-7005 2182 or e-mail health@independent.co.uk. Dr Kavalier regrets that he is unable to respond personally to questions.