Canine Toxic Epidermal Necrolysis, TEN

Toxic epidermal necrolysis (TEN) is a life-threatening, ulcerative skin disease that occurs rarely in the dog and cat. It involves the mucous membranes and skin surfaces and causes death of tissues. Necrosis of the mucosa of the trachea, large bronchi, pharynx and esophagus can also occur. This condition is often associated with an underlying infection, drug reaction, or metabolic disorder.

TEN is characterized by large, painful, ulcerative areas on any part of the body, but particularly on the head, footpads, and mucocutaneous junctions (transitional zones between the skin and mucous membranes in the mouth, nose, etc.) The disease can mimic a massive second-degree burn. The necrotic outer layer of the skin (epidermis) separates from the dermis to form variably sized blisters, which rupture, forming ulcers. Ulceration often induces a secondary dermatitis. In dogs, the disease is often associated with some predisposing conditions, such as staphylococcal infection, drug administration, or cancers. Fever, loss of appetite, shock, and even death may be a consequence of TEN.

Diagnosis What causes the disease is unknown. The diagnosis is based on history, clinical signs and skin biopsy. Biopsy of red non-ulcerated areas reveals acute necrosis of the entire thickness of the epidermis and the formation of subepidermal blisters (vesicles). Additional tests may be required to include a hemogram, serum chemistry profile and analysis of the urine. Common abnormalities include leukocytosis, electrolyte abnormalities that can cause heart failure, hypoproteinemia, and abnormal kidney function.

Treatment Supportive topical therapy with astringents (remedies that have a 'binding' action on tissue), intravenous fluid therapy, and systemic antibiotics usually is indicated. Corticosteroids use in the treatment of TEN is controversial. Antiinflammatory doses (1.1 mg/kg/day) can be tried in some cases. The underlying disease must be identified and treated concurrently if TEN is to resolve.

Prognosis The prognosis is poor as TEN has a high mortality rate due to fluid and electrolyte loss through the damaged epithelium.

References
1. Nesbitt G.E. & Ackerman L.J. Canine Immune-Mediated Skin Diseases. In: Canine and Feline Dermatology: Diagnosis and Treatment. Veterinary Learning Systems, Trenton, New Jersey
2. Results AFIP Wednesday Slide Conference - No. 27 8 May 1996, Division of Comparative Pathology, John Hopkins University, MD

Go Pets America recommends seeking the advice of your local veterinarian for the most appropriate vaccination program and for the diagnosis and treatment of your pet's health problems. For vaccination requirements please contact your state and local licensing authorities.