Fig. 5
a The 5 mm diameter tissue samples from the wounds’ center stained with hematoxylin and eosin were characterized microscopically as having a focal ulcer (ulcer not shown in this photo) with an overlying neutrophilic crust containing small colonies of cocci bacteria and numerous yeasts. In a, the epidermis is moderately hyperplastic and the dermis is thickened by abundant granulation tissue (associated with wound healing) composed of numerous small blood vessels and thick collagen bundles interspersed with small to moderate numbers of macrophages. b Higher magnification photomicrograph showing the superficial epidermis at left and bottom, which is heavily infiltrated by neutrophils, most of which are degenerate or necrotic. At top right is a serocellular crust that contains degenerate neutrophils, erythrocytes, necrotic cell debris, colonies of bacterial cocci, and moderate numbers of yeasts, presumed to be Saccharomyces boulardii