It could be an allergy to the deer jerky if you never had it before. If no problem before it could be contact dermatitis due to something you are allergic to. It could be a staph infection. What does it look like, tiny red dots, large irregular flat or crusty or blisters etc.?
it could be anything...try te tree oil..it is a naturall anteseptic..then put olive oil overnight..see how it goes...medication is sometimes not the wy to go..its probbably serious dry rubbing from contant irritation..maybe is it where ur shirt touches ur skin? it could be the laundr detergent...reevaluated everything that has come in contact with that area. but yes tea tree oil is the best