Is this Seborrheic Dermatitis?

I moved from Hawaii to Texas. I was in 5th grade and didn't have any of this dry skin behind my ear that always comes back until 6th grade. And I would only drink maybe 2 gles of water within 6 months. And I just started drinking 1 gl a day (Started 2 days ago) and my Seborrheic Dermatitis has started to disappear. Is this still Seb Derm or just lack of water?