I know, it is horrific, I keep fake nails, because if I don't, I scratch till I bleed, the fake nails prevent me from doing that :)
I tried tar shampoo until the hardness of plaque got softer on my scalp. Then i use Tresamme shampoo & conditioner with Argan oil in it (black bottle with blue print on it) and when getting out of shower pat dry the nape of back of my neck where scalp meets neck and keep it a little moist and then apply (JAR ONLY) of Cetaphil lotion to the nape of where neck meets scalp -really coat it good too. Keep doing this for about a month and a half and you WILL notice a difference. IN the meantime drink lots of distilled water..
I had it bad on my scalp and I now take Tremfya it is awesome been free and clear for year
Itch till it bleeds is my motto . Husband thinks I'm crazy. Glad there are more like me