Could Skin Irritation Be Due To Worms?

Sir, I had some skin irritation an I consulted a dermatologist. He said its psoriasis , some skin problem and prescribed some medicines. Its two years now but the problem of dryness,itching still remains. There is occasional itching in the anus. I took some medicine for worms, and I saw that my irritations on skin were less visible. Is the skin irritation due to worms or its my illusion