Itching nearbuttocks, private and legs.

I have 2 issues 1. I used heater in winter near my legs which made a prolonged itching on both legs below knee on outer side. 2. One day i returned from hard physical work. After few days a ringworm type shaped raised near my private part, knee and near stomach. It keeps on spreading and a large red area was made near my private part which always feels itchy. It has been 1 year i am facing the probem. I consulted many doctors online took many medicines. But still i am having the probem. I am also taking anti allergy medicine but no medicine is making me relief. I am now feeling very much itchy. I am presently working in office where we have to sit for long hours. I think working long hours while sitting makes sweaty resulting in increasing the problem. Please suggest me a suitable medicine so that i can get relief from long allergic issue.