S.B.
It sounds like a spider bite to me. Unless you are allergic to mosquitoes. My friend swells up like a puffer fish when she gets bitten by mosquitoes. The bites just welt up on her. We know it's not spiders because it happens when she's just outside bbq'ing dinner.
Regardless of what it is, you're obviously having a reaction and you should call the doctor about it.
Best wishes!