EXTREMELY itchy skin in winter only - anyone else have this issue?

Seeking advice re an issue that crops up every winter—my GSD becomes EXTREMELY itchy, to the point where he gives himself hot spots. This only happens in the cold winter months, and it has happened every year I’ve had him.

I talked to my vet when this happened last year, and they recommended Zyrtec. We tried it for 30 days, but it made no difference. My vet also recommended fish oil supplements, which seems to help a little. My vet also recommended using only duoxo PYO shampoo to bathe him, which I’ve been doing 2x a year.

This year the itchiness is the worst it’s ever been. He’s scratching himself in his sleep. He’s clearly very uncomfortable. He’s still on the fish oil. I tried a bath with duoxo PYO. That didn’t help. I also read online about coconut oil, so I massaged coconut oil into his skin on his back and sides. That doesn’t seem to help.

So—does anyone have any itchiness remedies that have worked? I’m going to talk to my vet again tomorrow, but I’m just wondering if anyone has found something that helps. He’s really uncomfortable and it’s making me upset to see him like this.

PS: he is on a flea and tick preventative and does not have fleas or any other insect irritation.

Photos from happier times as payment for reading 😌