Hunter skin problem

Hunter been having this skin problem since the beginning of December. It's like he has hives with redness and itchiness. We first thought that it must of been the laundry detergent so we've switched to free dye & perfume and washing it 2 times, but stil nothin. We've been giving him allergy medication morning, noon and night with oatmeal baths which does bring the redness away. But still, NOTHING!! So now I've had it, I'm bring in the big guns.. I've called the doctor. I'm going to see if they can help. Jason has the same problem but to weird things. We know it's not the dogs but it might be the grass they roll in or soemthing. Who knows but it is frustrating...... >:(