I use to lay in poison ivy at the top of a bauxite mine and shoot snakes and turtles in the mine. I normally didn't realize it was poison ivy until I was getting up and getting ready to go back to the truck...
Chiggers are a whole 'nother matter. But either they didn't live in the poison ivy or my meds keep them away. I know iron sulfate pills will keep you from being food for any hungry bug.....