When it comes to treating seb derm it is best to avoid western medicine because the topicals are so harsh and can cause especially long term/permanent damage to your skin. And anyway, again western medicines just tries to cover up the problem; it doesn't attack the underlying cause.
It is much safer to treat seb derm from a natural/holistic point of view and you are much more likely to gain long term benefits from doing so.
Firstly you need to assess what is causing the underlying problem. Ruling out candida albicans is a good start. Try taking extra virgin coconut oil, caprylic oil, olive leaf extract and garlic all for one week each in rotation so as the yeast does not build up an immunity against these natural anti-fungals. At the same time you need to avoid all refined, processed, hydrogenated and pre-packaged foods as well as high carbohydrate foods like pasta, rice, noodles etc. because the yeast love these type of foods. The optimum diet would be one high in fruit, vegs (no potatos), fish, white meat and nuts/seeds.
After following the above for 1-3months including the supplements, you can follow up with a parasite cleanse that mostly consist of Black Walnut Hulls as well as other ingredients to kill any problem causing organisms.
Now your body has removed the bad yeast, it is time to rebuild it with the good microbes. Avoid buying store-shelved probiotics that are on the whole pretty useless. You need to make your own. You should start drinking Kefir, Kombucha Tea and Apple Cider Vinegar. These three items will replenish your system totally with probiotics and maintain a healthy intestinal flora which is what you ideally want. The first two items can be made easily at home while the ACV can be store bought but should be organic and "with mother".
If you don't see any improvements with this then you it's likely you have an underlying hormonal problem that needs rebalancing. But it would be surprising if you didn't see any improvements as the above method is extremely powerful and has been used for centuries.