Altered immunohistochemical staining for desmoglein in skin biopsies in canine pemphigus foliaceus.

In this study, 50 cases of canine pemphigus foliaceus and 49 cases of canine superficial pyoderma were examined by immunohistochemical staining for patterns of desmoglein expression. In 31/50 (62%) of pemphigus foliaceus cases, there was an altered staining pattern for desmoglein consisting of distinct clumped deposits at the periphery of keratinocytes and/or dark cytoplasmic staining of acantholytic cells (consistent with internalization of desmoglein). In contrast, desmoglein staining in biopsies from cases of superficial pyoderma was diffusely pale without evidence for clumping or distinct internalization. This study demonstrates that epidermal desmoglein expression is altered in some cases of pemphigus foliaceus in dogs and suggests that immunohistochemical staining for this protein may be useful in diagnosis.