Q: By definition, what is the difference between Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)?


Answer: 

Stevens-Johnson syndrome (SJS): There is  less than 10 percent of the skin detachment of the body surface. And, involvement of mucous membranes are more than 90 percent of patients, usually at two or more major sites such as ocular, oral, and genital.

Toxic epidermal necrolysis (TEN): There is more than 30 percent of body surface is involved, and though mucous membranes are involved but not as distinctly as in SJS. 

In between or overlap cases are called SJS/TEN.