Use of intravenous immunoglobulin in toxic epidermal necrolysis and Stevens-Johnson syndrome: our current understanding.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN, Lyell's disease, syndrome) are considered to be part of a spectrum of adverse cutaneous drug reactions with increasing severity and extent of skin detachment, ranging from SJS (less than 10% body surface area skin detachment, 1-5% mortality) to TEN (greater than 30% skin detachment, 25-35% mortality). Both SJS and TEN are characterized morphologically by ongoing apoptotic keratinocyte cell death that results in the separation of the epidermis from the dermis. Recent evidence is supportive of a role for the death receptor Fas and its ligand FasL, in the pathogenesis of keratinocyte apoptosis during TEN. This Fas-mediated keratinocyte apoptosis that causes epidermal detachment in TEN can be inhibited in vitro by antagonistic monoclonal antibodies to Fas and by intravenous immunoglobulins (IVIG) which have been shown to contain natural anti-Fas antibodies. Over the last 6 years, numerous case reports and 8 non-controlled clinical studies containing 9 or more patients have analyzed the therapeutic effect of IVIG in TEN. Taken together, although each study has its potential biases, 6 of the 8 studies point towards a benefit of IVIG used at doses greater than 2 g/kg on the mortality associated with TEN. Hopefully, these studies will serve as the basis for designing a prospective controlled trial in the near future; as such, an approach appears the only way to definitively determine the therapeutic potential of IVIG in TEN.