I still don't know why many of you do not believe you have certain dermatitis which cause seemingly dehydrated looks on your skin.
Skin barriers can recover easily without the disruption of external factors ( fungal, bacteria etc) just like those people who have fire burned skin could recover within a few months and they do not have visible pores or dehydrated look.
Malassezia is commensal which means most people have it without many problems but under certain conditions they can over grow and cause many different skin problems. They can invade skin especially when the skin barriers are weak and damage (by soap or harsh skin products) or the immune systems are weak.
Two years ago, I started to have many acnes and greasy face after using facial foam with soap base (I already had mild dandruff before this). Most acnes disappeared after a few weeks of tea tree oily treatment but I started to have many whiteheads, blackheads and enlarged pores, skin was still oily. I guessed that's the result malassezia escaped from the upper layer and moved to pores. I squzze some whiteheads and blackheas from my nose and found they were just similar to dandruff just like dandruff in facial pores. I found the same type of dead skin around my neck, my chest and my back (I got acnes around these spots too but now I know they were indeed Malassezia/pityrosporum folliculitis). I knew all this mess was caused by fungal after doing my own research. Even the skin oil was very irritating since it was no longer the same skin oily after metabolizing my malassezia. I also found an article from a dermatologist and he said "Skin looks dehydrated but in fact it is inflammed". I was quite sure this was malassezia dermatitis which is still not known by many dermatologists and patients.
I started to try some antifungal topicals and they did not work quite well, I guess malassezia infected too deep for those topical to reach the spot. Oral antifungal was the solution to me. I found itraconazole has the lowest side effects among all others, I used this before to treat my fungal nails. I took 200mg tiwce a day for a week and stoped for 3 weeks and repeated the same for 2 months. After 8 weeks, my smooth skin came back without the greasy feeling, dandruff stopped, most whiteheads and all acnes on chest and back were gone. Malassezia is tough occupants and they are very hard to eliminate so I take one 200 mg itraconazole every 3 weeks to keep it in bay at the sametime I have my liver function monitored too but I have no issue with my liver function by now.
Many dermatologists refused to treat malassezia as they think it is commensal instead they prescribe antibotics which make the skin problems worse, the reason is simply antibiotics kill good bacteria which can live against malassezia.
The weakened skin barriers lead to infection of bacteria or fungal, while the skin inflammation is the real cause. Skin inflammation do not have to be red but in many cases they can be invisible, people just do not realise this.
I hope my stories can add some insights to people who insist in skin barriers play a big role to this dehydrated skin problems. I do not mean malassezia causes problems to everyone but try think about every possiblilties and not to stick to one route. It's alwasy trial and errors when dealing this kind of frustrating problems.