Hi bcbeans,
Just a thought, but could your boy have a pollen/dustmite allergy?
GSD's can be prone to allergies. Had our old girl pts in march, she was 15 years old and had had allergies all her life. Due to other med conditions, she was unable to take medication to ease the allergies (in fact she could have no meds for anything at all), but I found that by washing the 'hot' spots down each day with plain, warm water and dabbing dry, then applying a good dollop of aloe vera gel helped her a great deal. It takes its time to start to work but there was a great improvement - even the vet was pleased with how well she did. It did have to be done daily though and she needed it on all 4 paws, her chin and all her tummy, it would take an hour each morning just to make her feel comfortable for the day and during summer, I would redo her at night. Not that I minded, she was worth every minute :)