are you sure they're all mosie bites and not a rash?
i never get bitten, but then, i eat a lot of chocolate and sweets, sandfly's, mosquitos and other insects hate sweet blood..
my kids always were allowed chocolate and sweets, their teeth were always fine and they never got bitten, and if they did, was very few an far in between :)
failing feeding him up on yummy chocolate (which being a high form of antioxidants is very good for the heart), over here we have a product called betadine, its an iodine based ointment and works well on white tailed spider bites (which i've had numerous), bee stings, insect bites and stinging nettle itch (the one i hate the most)..
betadine is fantastic.