The family physician diagnosed toxic epidermal necrolysis (TEN) because >30% of the patient’s skin was desquamating.
Stevens-Johnson syndrome (SJS) is diagnosed when <10% of the body surface area is involved, SJS/TEN when 10% to 30% is involved, and TEN when >30% is involved. The pathogenesis of SJS, and TEN remains unknown, however recent studies have shown that it may be due to a host-specific, cell-mediated immune response to an antigenic stimulus that activates cytotoxic T-cells and results in damage to keratinocytes.
Drugs most commonly known to cause SJS and TEN are sulfonamide antibiotics, allopurinol, nonsteroidal anti-inflammatory agents, amine antiepileptic drugs (phenytoin and carbamazepine), and lamotrigine. Mycoplasma pneumoniae has been identified as the most common infectious cause for SJS. Other agents or triggers include radiation therapy, sunlight, pregnancy, connective tissue disease, and menstruation.
The epidermal detachment seen in TEN appears to result from epidermal necrosis in the absence of substantial dermal inflammation. Lesions may progress to form areas of central necrosis, bullae, and denudation.
Fever >39° C is often present. Severe pain can occur. Skin erosions lead to increased insensible blood and fluid losses, as well as an increased risk of bacterial superinfection and sepsis. These patients are at high risk for ocular complications that may lead to blindness.
This particular patient was stabilized with fluids and transferred directly to the burn unit for intensive care. The sulfa antibiotic was stopped since it was likely the triggering agent.
Photo is courtesy of the University of Texas Health Science Center at San Antonio, Division of Dermatology. This case was adapted from: Milana, C. Smith M. Hypersensitivity syndromes. In: Usatine R, Smith M, Mayeaux EJ, et al., eds. The Color Atlas of Family Medicine. New York, NY: McGraw-Hill; 2009:750-755.
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