Could just be a bad year for him. Could be that he's developing new allergies. Could be he's had some mild flea exposure -- dogs and cats with a flea allergy will sometimes erupt after a single bite. Could be something more serious -- the coat can get dull and the skin dry with a variety of systemic and metabolic diseases. You might want to keep an eye on him to make sure nothing else is out of the ordinary (change in appetite, change in water consumption, change in frequency or volume of urination).
As far as symptomatic treatment, there are some good emollients available (Douxo makes a particularly good one that doesn't smell bad, IMO) designed for dogs with seborrhea but also effective for generally dry skin. Changes in diet can help with these sorts of things -- though diets that are better for the skin (that is, richer) can cause GI upset in some dogs. Fish oil capsules seem to be helpful for some dogs, too.
The good topical products will usually only be available through your vet, though, and they may be able to pick up on things from looking at the skin and the dog that aren't apparent to you.