PMC3995397_01
Clinical appearance of the ulcer 2 months later. The ulcer on the fifth toe had expanded with surrounding small erythematous, bullous lesions, while the ulcer on the dorsum had exposed the joint capsule.
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F1
Two months later, the ulcer on the fifth toe had further expanded with surrounding small erythematous, bullous lesions, while the other ulcer on the dorsal foot had become deeper, exposing the joint capsule (fig. 1).
Hematoxylin- and eosin-stained section of the second biopsy specimen obtained from the bullous lesion showed leukocytoclastic vasculitis with fibrinoid degeneration in the reticular dermis and subcutaneous tissue (a). The first biopsy specimen obtained from the skin around the ulcer on the dorsum also presented perivascular infiltration of inflammatory cells and fibrinoid degeneration as well as necrotic lesions of the vessels in the dermis (b). Immunohistochemistry for VZV in the second biopsy specimen (c) and the first biopsy specimen (d) is shown. Positive staining of endothelial cells and inflammatory cells around the vessels and connective tissue in the dermis and subcutaneous tissue was observed in both specimens. On the other hand, positive staining was noted in keratinocytes only in c and was negative in d, representing the clinical features of bullous changes.
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F2
Leukocytoclastic vasculitis with fibrinoid degeneration was also seen in the reticular dermis and subcutaneous tissue as it was in the findings from the first biopsy specimen (fig. 2a,b). VZV (Novocastra Laboratories, Newcastle, UK) was positive in keratinocytes inside the vesicles, fibroblasts, inflammatory cells and endothelial cells in the underlying dermis (fig. 2c). VZV was identified on a virological culture of a swab. We also performed immunohistochemistry for VZV in the first biopsy specimen and confirmed positive staining in the cells in the dermis and subcutaneous tissue, including endothelial cells, with negative staining in keratinocytes (fig. 2d).