A Case of Anaphylactoid Purpura with Multiple Blister Formation: Possible Pathophysiological Role of Gelatinase (MMP-9)

A 10-year-old Japanese male with multiple blister formation and palpable purpura in the course of anaphylactoid purpura is described. Histologically, the lesions showed leukocytoclastic vasculitis in the upper dermis with subepidermal clefts. Blister fluid showed matrix metalloproteinase (MMP) 2 and MMP-9 gelatinolytic activities using zymography. These enzymatic reactions, especially that involving MMP-9 derived from polymorphonuclear leukocytes, might play an important role in the pathophysiology of this condition.