Could this be an std symptom or maybe just a rash or skin irritation?

on the side of the pines next to the head is red and very hard like a calluse,the skin is peeling like crazy,it just started 2 days ago and its the size of a pea,it is not getting any worse but it doesent seem to get better, it looke very dry,there is no bumps or anything else strange|||why dont you go see a doctor I'M SURE HE/SHE CAN TAKE CARE OF IT.