Is an unpopped blister a chatzitzah? I have developed two blisters on one foot and one on the other, and I generally try to avoid puncturing blisters, prefering instead to let them heal back into the body on their own. I know that, generally, flaps of dead skin are supposed to be removed before immersing in the mikvah (which I am planning to do this coming Sunday night).

Must I puncture the blisters to release the fluid before going to the mikvah or treat them in any other special way? If I do, or if they happen to pop on their own, how much effort should be made to remove the remaining dead skin? (I'm worried that if I scrub too hard and remove too much skin, I will increase the risk of infection.)