On day 1, in the area of the bulla, are visible (a, c) rounded (black arrowheads) and fusiform or pear-shaped (grey arrowheads) cystic spaces containing rounded bodies (c, white arrowheads); some of the spaces are arranged in rows and some are connected by a thin epithelial line (c, dashed arrow). (b, d) Fluorescein visualises some of the cystic spaces (arrowheads) and lines (d, dashed arrow) and seems to be pooling in a relative surface depression (d, bowed arrow). The plain arrows in (c, d) indicate a curved line implying an edge of epithelial sheet (the black and grey arrowheads are placed in corresponding locations in all 4 photographs; b blue filter)

(a, b) Survey of a large bulla (arrows), (a) before and (b) after the application of fluorescein. In the area in frames, shown in (c–e), a pear-shaped and a fusiform cystic space (grey arrowheads) connected by an epithelial line (d, arrow) is visible. The cystic spaces contain rounded bodies (d, white arrowhead) and (e) stain green with fluorescein (the grey arrowheads are placed in corresponding locations)

The same large bulla (arrow) as in Fig. 5.3. (a, b) Survey. For orientation, the arrowheads indicate the same cystic space. The area in frames shows (c) variously shaped cystic spaces (grey arrowheads) containing rounded bodies (white arrowhead) and an epithelial line (arrow). (d) Some of the cystic spaces stain green with fluorescein (the grey arrowheads are placed in corresponding locations; (c) is a composed photograph)

(a, b) Pear-shaped cystic spaces (grey arrowheads), containing rounded bodies (white arrowheads), and epithelial wrinkles (b, arrow). (c) A large bulla (arrow) situated in an area showing many small blisters (arrowhead) which seem missing within the rim adjacent to the bulla (double arrowhead). (d) Epithelial detachment captured in the bulla (arrow) shown in (c); its contents are clear

(a) Two large bullae (arrows) situated in an area showing many blisters (arrowheads). Between the double arrowheads a relatively smooth rim surrounding the bulla is visible (cf. Figs. 4.​13 and 5.1). (b) A heart-shaped area (bowed arrow) suggestive of epithelial disruption with displaced epithelial flaps (grey dashed arrows) at its lower edge. The surroundings show rounded cysts (arrowhead) and epithelial lines (white dashed arrows) (cf. Fig. 4.​10). (c) Fusiform cystic spaces (grey arrowhead) containing rounded bodies (white arrowhead)