Figure 4.

Skin biopsy findings. A) 100×. B) 400×. A skin biopsy of the purpura was performed on Day 8. Hematoxylin and Eosin staining revealed the infiltration of lymphocytes and neutrophils with nuclear dust from the dermal papillary layer to the dermal reticular layer, and red blood cell leakage was observed around the capillary lumen with swollen endothelial cells and arterioles where inflammatory cells had infiltrated into the vessel wall. These findings were consistent with ANCA-associated vasculitis.