IMMUNOHISTOLOGICAL COMPARISON OF GRANULATED CELL-PROTEINS IN INDUCED IMMEDIATE URTICARIAL DERMOGRAPHISM AND DELAYED PRESSURE URTICARIA LESIONS

Urticarial dermographism and delayed pressure urticaria are two forms of physical urticaria which are well defined clinically and histologic ally. Previous studies have shown eosinophil granule protein depositio n in urticarial reactions, including chronic urticaria, solar urticari a and delayed pressure urticaria. To evaluate and compare the involvem ent of granulated inflammatory cells in urticarial dermographism and d elayed pressure urticaria, we studied sequential biopsies of induced l esions of urticarial dermographism and delayed pressure urticaria by i ndirect immunofluorescence, to detect eosinophil granule major basic p rotein (MBP) and neutrophil granule elastase. Biopsies from dermograph ic lesions at time 0, 5 min, 15 min, 2 h and 24 h, showed few infiltra ting eosinophils, with minimal extracellular MBP deposition, and a few infiltrating neutrophils, with minimal neutrophil elastase deposition , throughout the evolution of the lesions. Sequential biopsies of dela yed pressure urticaria at time 0, 20 min, 6, 12 and 24 h, showed eosin ophil infiltration with extensive MBP deposition beginning at 20 min, and neutrophil infiltration with variable elastase deposition beginnin g at 20 min. Control tissue specimens from normal volunteers showed ne utrophil infiltration and slight degranulation, but no eosinophil infi ltration or degranulation. Comparison of urticarial dermographism with delayed pressure urticaria showed marked differences in the patterns of infiltration. Delayed pressure urticaria, with eosinophil and neutr ophil degranulation, was strikingly similar to the IgE-mediated late p hase reaction. In contrast, eosinophil and neutrophil involvement in u rticarial dermographism was minimal. Considering the extent of eosinop hil granule protein deposition and the biological activities of the eo sinophil granule proteins, the findings in delayed pressure urticaria point to an important pathophysiological role of eosinophils in the di sease.