there is another possibility - psoriasis
go to the doctor and get it checked. it could be fungal, or it could be dermatological.
if it is fungal, the doctor will give you an antifungal cream. this will do nothing if it is psoriasis. if it is psoriasis, you will need a different cream, this will do nothing if it is fungal.
if it is fungal, the good news is, when it is gone, it is gone. although you do need to REALLy wash your clothes to kill it all. if it is psoriasis, you will have it for the rest of your life, but you can manage it, although like dandruff, it will keep coming back if you don't.