In future, rsvp, please just feel free to use a tiny dab of antihistamine cream if he's got bites or an itchy rash. My sister's dog is often covered in itchy spots with a rash. She's had so many tests, to no avail, they are about to give up! Personally, I think she has an allergy to something in the grass here, as apparently she doesn't scratch much when they are at their own house.
You can buy anti-itch preparations without a prescription from Petsupermarket.com I use them a lot for toys and treats, as they are reasonably priced and you don't have to spend much to get free P+P.
Glad to hear he's getting better!