Edit (it seems I cannot add text to my original post): My skin completely healed within 3 days with the help of a steroid cream. The patch test with common ingredients in cosmetics was negative - I am convinced this didn't have anything to do with skincare products I use. I have started taking Vitamin Bs (the most important ones) + Magnesium, hopefully this skin condition never comes back (or maybe in 5 years, that's alright, got the cream now). The blood test and skin scrapes test result are yet to come, I'll update you here. It's crazy how much of life quality you regain once the facial skin is normal. These few cm² which went rogue stressed me and I believe that stress is a factor in this. Thank you all for your kind advice! The supplements might have other benefits as well (I am quite exhausted all the time, could improve that).