Bites that contain "seeds"

My mom has been suffering for years with some type of bite, they appear like a pimple. They are very very itchy and when she scratches them there is some type of seed or egg inside the bite. In some there is a couple, in others up to ten or twelve of these seed things. Once she gets the seeds out they dry up but they scare her skin terrible. She has never gotten rid of them they will start to clear up and then she has another breakout somewhere else. The bites are mainly on her legs and butt and on her upper arms. If anyone can give us anytype help with figuring out what this could be we would be very grateful. Thanks candybar11.