What's wrong with my wrist?

My 15 year old sister was trying to fight with me by grabbing my wrist and shaking it to try and break it. It didn't break, but now I have a bunch of itchy skin colored bumbs all around where her hands were (they kind of look like fresh mosquito bites). There aren't a lot of itchy spots. There are only about 8 and each bumb is the size of half of a finger nail. I tend to get itchy rashes on my hands from using ipads or laptops that other people have used very often, but I've never gotten these bumps before. What's wrong and what should I do?