What can help rash/dry skin on an 8 year old?

My 8-year-old son for years has gotten a sort of rash on his arms (fold area) and occasionally on his legs (fold area as well). His doc has always prescribed triamcinolone cream and usually in a day or so it has gone away. I recently ran out and it's come back and can't get him to the doc right away and since it is not a life or death situation I've been trying some home remedies and Cortaid at home as per the pharmacist as he says this is close to triamcinolone but OTC. Now the rash is gone but he has severely dry skin, kind of wrinkly. He thinks he has "old man skin." What can help? Thanks.