LO has been developing blisters overnight on either the sack or at the tip of his p*nis. They appear to be clear inside. Sometimes just just disappear, sometimes they pop and the area is red (and sometimes bleeds a little) but then heals pretty quickly with Grandma Els.LO doesn't complain during diaper changes and the rest of his bottom is completely clear. No redness or anything. Just these random blisters that are about the size of a pencil eraser. He'll get 1 or 2 at a time and they'll heal, disappear and then come back in a day or two.
We can't figure out what is causing it. LO is in blueberry diapers at night with a disposable liner and cotton fitteds during weekend days and disposables at daycare.
Does anyone have any ideas?