Why do sls free shampoos destroy my scalp?

[Indecisivejo]

Literally every time I try a sulphate free shamp my scalp pcoriasis flares up! Scalp gets so sore itchy and flaky! Weird!

Me too, and I don't even have psoriasis. As soon as I try one of the more natural shampoos, my scalp fills up with sore bumpy spots.

I have no idea, all I know is that I bought one by accident and it didn't clean my hair. At all. Yuck.