Yes. It is permitted for one to touch all areas that were not listed above in Shulchan Aruch. Thus one may scratch his arm, leg, stomach, and back prior to washing.
- Admur in Siddur writes that if one slept a temporary sleep of 60 breaths he is to wash with a blessing, although prior to doing so he is to touch the normally covered areas of the body. See Ketzos Hashulchan 2 footnote 21 and Chapter 4 Halacha 17. ↩