What Causes Prickling Sensations In Legs And Hands?

Hi my 4yr old daughter has been getting prickling symptoms in her feet up to knee level - it used to be just in her car seat (I thought initially it was positional related) but also early nighttime, and getting very distressed and upset with jumping and kicking legs. It can also wake her up from sleep. But now she is complaining of the same symptoms down her right arm and hand and during the day as well. I have commenced her on a vitamin and mineral supplement. She is well in all other respects and eats a good and varied healthy diet. Any advice much appreciated.