Acid hydrolases in experimental and spontaneous bullae.

The activities of eight acid hydrolases have been measured in blister fluid from various bullous disorders and from experimental suction blisters. The levels of all enzymes increased dramatically for at least 24 h after induction of the blister. No correlation was found between acid hydrolase activity and any individual disease. The levels of activity in spontaneous bullae were similar to those reached after 24 h in experimental suction blisters which had been raised on previously inflamed skin. We conclude that the release of acid hydrolases may be a consequence rather than the cause of blister formation. This conclusion is supported by the lack of inflammatory response to the i.c. injection of blister fluid into normal skin.