Have you changed anything in Stephen's diet recently? Sometimes sensitive skin (itching, dryness) indicates an allergy but many times it's simply associated with a deficiency of omega 3 and omega 6 fatty acids.
What are you feeding Stephen? I found that once I switched to 1/2 wet food, Cleo's dandruff completely disappeared. They are completely on wet food now. A good brand of food (dry or wet) should also have more Omega fatty acids that should help her skin.