Hello again, and thanks for your reply.
If his skin looks scaly, it could be dry, or he could be exhibiting symptoms of allergies to ingredients in his food, environment, or fleas. Even though you don't have a flea problem in Utah, which is great, if you ever find the need to treat your cat, flea collars are not effective and cause adverse reaction in cats. If you do ever need to use any flea treatment, only use one sold by your vet, like Advantage or Frontline.
If the Friskies dry food contains corn, corn gluten, wheat, soy, dairy products and/or artificial additives (colorings/flavorings) and preservatives, these are all common allergens for cats, and can cause skin reactions. Some well recommended brands of cat food, which contain no allergens, are Wellness, Felidae, Innova, Neman's Own Organic and Natural Balance, just to name a few. These are available at major pet supply stores. It's also possible that he's experiencing an allergic reaction to his kitty litter, so you might try gradually changing your current brand to one that is unscented, as dust-free as possible, and see if this improves the situation.
Dry, scaly skin may be caused by dry conditions inside the house, and running a humidifier in the room he's in the most, will help add moisture back into the air. Some underlying medical conditions can also be responsible for dry, scaly skin, so an evaluation by the vet, and having a skin scraping (painless) analyzed under a microscope, will help more accurately diagnose the problem.
There are several excellent skin/fur products, made by Drs. Foster and Smith, which you can find on their website, and/or in pet supply stores:
Offering some oil from canned tuna, salmon or sardines, daily, will add healthy Omega 3 fatty acids to his skin and coat, and encouraging drinking of water is also necessary to maintain a healthy coat and less dry skin. Combing/brushing several times daily, will also help bring natural skin oils to the surface.
I would first recommend a vet visit, to have this area of his tail/back evaluated, to find if there is a medical cause for these symptoms. If all is well, hopefully, then try employing some of the above suggestions, to decrease his dry skin, and I'm sure your vet will have some additional ideas for you, too.
I hope all will be well.