Itchty Dog - Dry skin, nose

My 5 year old Ace has always had dry skin. I have to put Aquafor lotion (like vaseline) on his nose every day. Sunscreen too. He's had lots of skin flakes in his fur recently too, more than usual. That, and we are averaging about 105 degrees each day, even though he's inside most of the time he still spends some time outside.

Lately though, he's been very itchy. He scratches all day. I've checked him for fleas, and he's clean. I've bathed him with a dry skin shampoo for dogs, and also used my Furminator on him a ton, but to no avail.

What can I do? What can I check for? I feel bad he's itchy, but it might just be his genetics.