Page 1101 - Veterinary Immunology, 10th Edition

results in the development of lesions mimicking Stevens-Johnson
VetBooks.ir syndrome.) The skin lesions are infiltrated mainly by CD8 T cells
+
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and fewer CD4 cells. Many different drugs may trigger these
responses, but common inducers in dogs include trimethoprim-

potentiated sulfonamides, β-lactam antibiotics, penicillin, and
cephalexin. Beginning about 14 days after drug exposure, the skin
begins to blister and slough. Animals develop generalized illness,
including dyspnea, vomiting, fever, and weight loss. In dogs,

sloughing of the epidermis occurs over the nasal planum, the
footpads, and the oral, pharyngeal, nasal, conjunctival, and
preputial mucosa. Fluid loss leads to electrolyte imbalances,
whereas life-threatening secondary infections are common. Biopsy

specimens show extensive epidermal cell death.
Treatment involves immediate withdrawal of the offending drug
followed by symptomatic treatment, including fluid replacement.
Corticosteroids should be avoided since they increase the animal's

susceptibility to skin infections and worsen the prognosis.
Antibiotics should only be administered if skin infections occur.
Intravenous administration of high doses of human
immunoglobulins have been used successfully to treat this disease

in dogs. It is believed that these immunoglobulins block
CD95/CD95-ligand interactions and prevent keratinocyte apoptosis
(Chapter 41).

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