Thank you for the suggestions and comments. We did give him a bath with special shampoo the vet gave us. It seemed to help. I'm not quite so itchy now. The dog did not like the bath, though, and afterwards he was licking himself and threw up. Now this morning he threw up again. I think he's sick. Oh, boy, just what I need!
Do you have any red spots, bites bumps? Is the dog itchy. Just making sure it's not scabies or fleas. I would go back to the allergist and see maybe you have become allergic.
Believe it or not, but true allergies to dog dander is unusual. Cat dander is highly allergenic, though.
Jaybay is right, it could be to a shampoo or other product that was applied to his coat.
Wash him with a mild baby shampoo and see if that doesn't help. See an allergist if it doesn't get better, because while an allergy would be unusual, it is certainly not impossible.
I get some itchy bumps if I hug the dogs or are very close to them sometimes, but our vets have said that's a common skin reaction that some people have and they really don't know why. Sometimes I get the bumps, sometimes I don't.
You could be allergic to whatever he was recently shampoo'd with. Try using a quality, hypoallergenic shamppo from your vet and see if that doesn't help. It's not the hair that people are allergic to in animals, but the dander - bits of skin cells, etc. The cleaner the dog is, the less dander to cause you trouble.
It's probably time to go back to the allergy doctor to determine exactly what you're reacting to. Until then, keep up the benadryl, avoid close contact with the dog, and try to maintain a "clean" room - like your bedroom - where the dog isn't allowed. If your symptoms start including asthma, you need a place to go where the allergen isn't present.
My husband had terrible allergies to dogs, cats and horses along with all the usual airborne things. I pretty much forced him to adopt Travis in 1990 - we found him near death at the side of a gravel road. No way could I leave him there! Anyway, as long as Hubby didn't handle him too much, and we kept him out of our bedroom, he was fine. After about 5 years of allergy shots, he can roll around with any dog with no problem.
Best of luck to you! :-)