We use 3 fingers on each hand, excluding the index and thumb. So far they look okay-ish. They do have some callouses (sp?). Sometimes I put a tiny bit of Neutrogena hand cream on one hand, and use the other for testing, and the following night I switch.
You can also try alternate test sites. Some people use the toes at night. Others test at the area at the base of the thumb, some even on the forearms.
Mom to 2 boys (9 and 10), oldest dx in Oct. '06
Pump MM522 w/ Sure-Ts infusion sets since July '10
Previously pump Deltec Cozmo w/ Contact-Detach sets
"He attacked everything in life with a mix of extraordinary genius and naive incompetence, and it was often difficult to tell which was which." ~ Douglas Adams