I hope this helps someone. I know how frustrating and embarrassing this condition is.
Sarah (Chicago, Il) on 02/15/2014:

I had seb derm on my face for years and it finally was cured after I started lugol's iodine applied topically. Another poster on Earth Clinic wrote about it curing his eczema and so I tried it after I read his post. After 2 days, it started to clear!
At first I diluted 3% lugol's iodine 50/50 with water and applied it with a q-tip. I held the q-tip on the spot for 60 seconds. It burned like the dickens, but it was worth it! After the second day, I held undiluted lugol's to the spots with a q-tip. After 7 days it was gone and I applied it every few days, thinking it would come back if I didn't. It never did and I stopped the lugol's application altogether.
Dairy and especially cheese is a huge trigger for my seb derm.
Please try lugol's if you have sebhorreic dermatitis. It has been a miracle cure for this impossible condition!