I too have had dandruff for a few years now. I am now using a antifungal shampoo (called Terzolin, containing Ketoconazole) about 1-2 a week and it's keeping the dandruff under control. I've also thought about trying to use it on my lips, but haven't so far ;-)
I don't know if the conditions are related in any way, my derm does not think so. It just seems like many people with EC also have other skin problems.