Suggest Remedy For Itchy Bumps

Whenever I come to work (which is an elementary school) I get occasional bumps that look and itch like moquito bites. When I left the house this morning I had nothing on me, about an hour after work my hand started itching and before I knew it there was a bump there that looked like a mosquito bite. By lunch another "mosquito" bite popped up on my chin, and now I'm just itchy all over. What could it be?