Could it be your laundry detergent? I had to use a hypo-allergenic soap on all our clothes and bedding when we had Cass. She used to break out in bumps like that and just doses of benadryl wouldn't take care of it. She had to get a shot of it from the vet. Just a thought though.. you should call the vet. Could be something in the food also. I'd eliminate one thing at a time to see if you can pin point it. Poor little Stella! Hope it clears up for you!