I have type 1, but I've suffered from psoriasis and cracked feet in the past. For dry feet I use Flexitol (I buy it from Boots), which has been brilliant. When I had particularly bad scalp psoriasis I actually went to the GP for medicated shampoo. Sounds extreme, but I'd gone to the barber and they couldn't cut my hair because it was so bad! My blood sugar control was also much worse back then, which I think was a big part of why it happened.