Detection of Apoptotic Epidermal Cells in a Dog with Toxic Epidermal Necrolysis

Abstract

It has been reported that apoptotic keratinocytes were not observed in dogs with toxic epidermal necrolysis (TEN). Here, we describe a dog with TEN in which apoptotic cells were found in the epidermis. A 13-year-old female mongrel dog was presented with acute and extensive erythema, vesicles and ulcerations, especially on the ventral skin and visible mucous membranes. The dog also exhibited anorexia and lethargy. The dog was administrated oral amoxicillin 5 days before development of the skin lesions. Histopathological examination of the skin lesions revealed a full-thickness epidermal coagulative necrosis with lymphocytic exocytosis compatible with TEN. Immunohistochemical analyses indicated that infiltrative lymphocytes were positive for CD3. In addition, TdT-mediated dUTP-end labeling (TUNEL) positive cells indicated there were apoptotic cells in the epidermis including keratinocytes. Based on these findings, T cell-mediated apoptosis of the epidermal keratinocytes was considered as a possible pathomechanism of epidermal necrolysis in the present case.