I am having similar issues with my male GSD. It started when the heat was turned on in the house, no signs of any thing prior. At first I thought fleas or allergic reaction to flea bite. It was at the base of his tail where his fur is the thickest. Vet confirmed no fleas but dry skin due to the weather/heat, etc. It went away and I noticed him doing the flea biting on his back. I looked and he did some damage, you could see the irritation from the biting at it in several areas, which has caused some fur loss. I wasn't to sure in what order to go in to get the area healed, so I first tried coconut oil directly applied and on food, didn't help. Next I went to miconazole and got old shirts to cover it when he couldn't be supervised, that worked a little bit but not enough. Next I went to Neosporin and that worked to heal it pretty quickly. I also used an anti itch cream because once he got to it I was starting all over
I gave him a bath using oatmeal/tea leaf shampoo and that seemed to relieve some if the dry skin. For the last 3 days I have been brushing him lightly and using a high force dryer to blow out the dry skin, the dryer does not get hot and he likes it. He is going to the vet on Saturday. He has been on a diet and I feel that he might have lost to much weight to fast so now I'm freaking out about that and I don't even know for sure. He will have a full blood panel and I have a doggie dermatologist on stand by. He is on a salmon/sweet Potato grain free diet. Treats are also grain free. He has no ear problems and every now and then he scratches other areas of his body but not enough to cause concern. I'm hoping it's just a matter of keeping the dry skin under control, because if he didn't have that he wouldn't be itching. I'm also considering getting him shaved if necessary starting next winter. I don't want to do that if I don't have to. I'm sure they are going to shave quite a bit on Saturday so his skin can air out. I was going to do it myself but I didn't want to knick any of the irritated skin.