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

Two Rare Cases of Feline Toxic Epidermal Necrolysis: A Novel Therapeutic Approach With Medical-Grade Honey

Toxic epidermal necrolysis (TEN) is an acute and life-threatening dermatological condition that is drug-induced and characterized by extensive epidermal detachment. These lesions should be protected from infection using a product that has a low risk of reactivity. Medical-grade honey (MGH) exerts antimicrobial and wound-healing effects while posing a low risk of exacerbating TEN. In this case report, we are the first to describe the use of MGH for wound management in two feline TEN patients. Case 1 involved a 1-year-old female British shorthair cat, while Case 2 featured a 1-year-old female mixed-breed cat. Both patients presented to the hospital with various symptoms, including fever, tongue lesions, and lesions in the abdominal area following ovariohysterectomy surgery. TEN was confirmed via histopathological examination. The suspected cause of TEN in both cases was the iodine present in the surgical scrub. Tongue lesions were addressed with a liquid diet, and all xenobiotics were immediately withdrawn as a precaution. MGH products supplemented with vitamins were applied to the abdominal wounds following a wound lavage with Ringer's lactate. Daily dressing changes were performed without discomfort, pain, or any adverse reactions. In both cases, debridement became evident after just 1 day, and the patients fully recovered after 12 days of MGH therapy. This case report demonstrates for the first time the successful use of supplemented MGH for wound management in veterinary patients with TEN. The patients did not have any adverse reactions to the treatment, while MGH dressings provided antimicrobial protection and wound-healing effects. Furthermore, these cases highlight the importance of rapid diagnosis and immediate drug withdrawal to increase the survival rate. Overall, supplemented MGH is a safe and effective method to treat TEN-related lesions in feline patients.

Cytotoxic dermatitis: Review of the interface dermatitis pattern in veterinary skin diseases

Interface dermatitis or lichenoid interface dermatitis refers to a cutaneous inflammatory pattern in which keratinocyte cell death is the essential feature. These terms have evolved from the originally described lichenoid tissue reaction. These lesions are the basis for an important group of skin diseases in animals and people where cytotoxic T-cell-mediated epidermal damage is a major pathomechanism. Yet, for largely historical reasons these commonly used morphological diagnostic terms do not reflect the essential nature of the lesion. An emphasis on subsidiary lesions, such as the presence of a lichenoid band, and definitions based on anatomical features, such as location at the dermo-epidermal location, may cause confusion and even misdiagnosis. This review covers historical aspects of the terminology, including the origin of terms such as "lichenoid." The types of cell death involved and the histopathologic lesions are described. Etiopathogenesis is discussed in terms of aberrations of immune/inflammatory mechanisms focusing on cutaneous lupus erythematosus, erythema multiforme, and Stevens-Johnson syndrome/toxic epidermal necrolysis. Mechanisms have most extensively been studied in humans and laboratory animals and the discussion is centered on these species. As interface dermatitis is firmly entrenched in dermatological parlance, rather than using "cytotoxic" as its substitute, the terminologies "interface cytotoxic dermatitis" and "panepidermal cytotoxic dermatitis" are recommended, based on location and extent of epithelium affected.

Apoptosis as a Mechanism for Keratinocyte Death in Canine Toxic Epidermal Necrolysis

In humans and dogs, toxic epidermal necrolysis (TEN) is a life-threatening dermatosis characterized by sudden epidermal death resulting in extensive skin detachment. There is little information on the pathogenesis of keratinocyte cell death in canine TEN. We studied the occurrence of apoptosis in skin lesions of dogs with TEN to determine if apoptosis contributes to the pathogenesis of this disease. Immunostaining with antibodies to activated caspase-3 and the terminal deoxynucleotidyl-transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labeling technique revealed positive apoptotic keratinocytes in basal and suprabasal epidermal compartments in 17 biopsy specimens collected from 3 dogs with TEN and 16 from 3 dogs with erythema multiforme (EM). There was no significant difference in the number of positively stained epidermal cells between TEN and EM. These results suggest that apoptosis of epidermal keratinocytes and lymphocytic satellitosis represent one of the early steps in the pathogenesis of canine TEN, as in the human disease counterpart.