Blister On Buttocks I'm Wondering What Would Cause A Blister-like Sores On Buttock (and Upper Back Leg) On A Child?

I'm wondering what would cause a blister-like sores on buttock (and upper back leg) on a child? - blister on buttocks

Some of the injuries appeared to have dried and scabs. It also has a wound on the back of his ankle, but it is very similar to a blister and were unsure whether the relationship