I know it can be caused by other things that feel irritating to them including fungus, skin irritants, and persistent high humidity. I don't think it's unreasonable than if the fur is heavy with oils to the point of clumping like mine was that it could have some ill effects considering the fur looked and felt very different when it was clean. One of the problems we had was that we lived in an RV so the humidity inside was high and compounded the problem. It pretty much went away once we moved into a house and improved as the temperatures lowered.
My first chin had very dry flaky skin so there were times I'd dust him every two days instead of every other day to help with that but it didn't seem to make much of a difference. My second chin has very healthy looking skin and his fur doesn't seem to slick down with oil near as easily.