if the shingles are not in a place where there would be direct skin contact (covered by clothing) you can go back to work when you can tolerate or control the pain. as a pre-school employee you most likely were exposed to the varicella (chicken pox) virus by one of the children (unless you have had shingles in the past and this is just a reactivation of the virus).
i work in a preschool classroom and have been diagnosed with shingles when can i return to school?