Antihistamines work better than sleeping pills for me! I have to make sure I get the no-drowsiness kind or I'll fall asleep at my desk.
I am allergic to bee and wasp stings, so I always carry my epi pen when I'm outside.
I've also had allergic reactions to mosquito bites, although they are not as severe as a bee or wasp reaction. Still, I have to take a dose from the epi pen if I get too many mosquito bites, or the sites will start swelling a lot.