a couple of months ago, a Chinese lady, who is in her late thirties and is a friend, was on business in China and whilst exiting the aircraft steps (no jetway) she fell and badly bruised her hip, thigh and lower leg.

now, although the bruising is long gone, the area on her lower leg in the area which was bruised, has started to grow quite heavy hair !

Now this lady, is typically Asian and as such has the usual hair free skin is now showing hair growth in the damaged area of her leg, and I mean the exact area and size of the original bruising.

I have never come across this before - any theories ?

Everyone is covered with hair follicles. Even those that don't appear to have any hair on their body. It is possible for an area that has been traumatized to cause hair growth out of these follicles that is darker and thicker than usual. In most cases it's the trauma results in more blood supply forming in the area. This increased blood supply can and will stimulate the hair growth you speak of.

Thanks for that Jamie,however, is this a temporary "growth" resulting from increased blood supply to the damaged area or will it be permanent. ?

If it is permanent there'll be a lot of old guys banging their heads against walls

Sorry I fail to see your joke dr PP. One of the main reasons I asked for clarification was because its not something I am fully understanding, however, and this may dampen your humour, there is a young lady in my mooban whose face is covered by long thick hair, I understand that this is from a birth mark. However funny it is not sad. It most definately is !!

It's difficult to say if it will be permanent. If new blood supply has been established around these follicles, she may see continued hair growth. The only real way to know for sure is to let the area fully heal and wait for the hair to go through its growth stages to see if it comes back.