For occasional reoccurring seborrhea dermatitis behind my ears, one day realizing that coconut oil had anti-viral and anti-bacterial properties, I put some on the effected scalp. Hadn't had any dermatitis since and it has been over a year.
As for my mild roseaca, I keep out of the sun, using a 50 sunblock and stay away from very spicy hot foods as both exposures seem to cause a flair up.
Coconut oil on the face I no longer do because I was told the large molecule can clog pores. I heard (very expensive) manuka honey from the continent down under is anti-viral, but you have to watch out for fake stuff.
At 24 I had my first experience of seborrheic dermatitis, and had it for about 2 years. I can honestly remember one girl commenting 'it looks like his nose is turning green', to be honest I couldn't care less what she said, but there were times when i felt so low I didn't want to leave the house. I might have been exaggerating, but my nose was going from small red marks, to be inflamed burn marks, to a yellow gewy substance which would eventually harden.
I tried so many things. At first the steroid cream I used did the job in the short term. But it was no long term cure I was comfortable with. If I stopped using it it was back in a week. Maybe less. So I stopped using that pretty early. I also used aveeno yeast cream, aloe vera (from a bottle and from a plant), going on a yeast free and sugar free diet (to be honest this lasted about a month and a half, and don't think I went completely all out. But tried to cut the main stuff out), and garlic- none of these things worked.
Funnily enough, when I went to the states, it practically seemed to go on its own.
Then I decided to use coconut oil. externally (100% coconut oil- the brand is pukka). I applied it about once every day, not very much was needed as it is a very oily product. Actually I started by using this and taking it internally, eating crushed coconut from a jar with a spoon. but now I just apply it externally. I've been doing this for about 4 to 5 months now, and it is already feeling like a miracle cure, so I hope it carries on like this! I only had one major flare up since, whereas before I was getting one every other week. I hope I'm not speaking to soon, but it's really helped my confidence, and probably changed my life for the better. And something so simple! Just gotta thank the people on this website (and this website for this).
Of course a downside could be seen as it coming back if I stop using it. But who knows, it might even go for good!