This condition is a blistering disease caused by an auto immune
response, where the animal or human is allergic to his own skin.

This is
very rare but does occur in Collies and other breeds.
Usually, you will not actually see the blisters, since they do not last long,
but will see the ulcers or sores resulting from the blisters.
The blisters usually appear in the groin, underarm or inside the mouth.

This condition is treated with steroid creams and/or oral medications.
Sunlight can aggravate this disorder, and bacterial infections may occur.
Inheritance is no known at this time, but breeding from dogs with
any type of auto immune disease should be avoided.

This condtions needs to be distinquished
from other skin problems.
Bullous Pemphigoid