My hand is really puffy and it itches a lot!?

Yesterday I was watching tv then out of nowhere my hand started to itch. I'm assuming something bit me. Not a mosquito though because it burns real bad and is swollen and itches a lot:/ anyways, what can I put on my hand to make it stop burning and make the swelling go down. I know lemon juice works and so does baking soda with hot water but it doesn't work for long. And i'm at work so i don't have any of that. Any suggestions ?