have you looked into threadworms which are strongyloides, look at my pictures in Image Gallery . type in sharkman in search bar . I use a black , cotton, lint free fine thread cloth to wipe out these fibers from my active itchy rashes mostly from my groin and anal area, I also have lots of different rash pictures from different areas of body. if they seem similar you should further investigate , if they are the same then there is a good chance you have a strongyle or roundworm infection of some sort. hope this info helps