Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are serious mucocutaneous adverse reactions, most generally generate by medications, defined by fever and vast necrosis and separation of the epidermis. SJS and TEN are considered a disease continuum and are diagnosed essentially by severity, based on the percentage of body surface involved with skin detachment.
SJS is the less severe condition, in which skin detachment is <10 percent of the body surface. Mucous membranes are affected in over 90 percent of patients, usually at two or more separate sites (ocular, oral, and genital).
TEN involves detachment of >30 percent of the body surface area (BSA). Mucous membranes are also involved in over 90 percent of cases.
SJS/TEN overlap defines patients with skin detachment of 10 to 30 percent of BSA. Mucous membranes are also involved in over 90 percent of cases.
Panel test:
· Immunopathology:
o Massive death of keratinocytes, excess CD8+ T cells, and possible involvement of FasL.
o MHC link in some cases, mainly in oriental but not Caucasian populations (HLA B15 (B75) with phenytoin or carbamazepine, or B58 with allopurinol).
