Weakness (Concentrated Evil) for holy clerics

I was thinking about how to handle some stuff that occured in AD&D where if holy clerics touched or used some items of extreme evil they would suffer damage. For example, if a cleric touched the altar of Tharizdun he would take damage or if a cleric read the book of vile darkness he would also take damage. I would guess that this should be a very rare weakness because normal evil items do not seem to cause harm just the truly evil ones. Truly evil items would have to be cleansed if possible for the cleric to be able to handle them. More than likely however the cleric would have to avoid them.

Weakness (Concentrated Evil) for holy clerics