Toxic epidermal necrolysis (TEN) is a rare, life-threatening adverse drug reaction with an estimated incidence of 0.4 to 1.9 cases per million persons per year worldwide and an estimated mortality rate of 25% to 35%.1,2 This dermatologic emergency is characterized by extensive detachment of the epidermis and erosions of the mucous membranes secondary to massive keratinocyte cell death via apoptosis, evolving quickly into full-thickness epidermal necrosis.
Primary treatment of TEN includes (1) prompt discontinuation of the suspected medication; (2) rapid transfer to an intensive care unit, burn center, or other specialty unit; and (3) supportive care, including wound care, fluid and electrolyte maintenance, and treatment of infections. Aside from the primary treatment, controversy remains over the most effective adjunctive therapy for TEN, as none has proven consistent superiority over well-conducted primary treatment alone. Therefore, established therapeutic guidelines do not exist.1-3
The use of adjunctive systemic therapy in TEN (eg, corticosteroids, intravenous immunoglobulin [IVIG], cyclosporine, plasmapheresis, granulocyte-colony stimulating factor) is based primarily on theories of pathogenesis, which unfortunately remain unclear. Activated CD8+ T cells are thought to increase the expression and production of granulysin, granzyme B, and perforins, leading to keratinocyte apoptosis. Fas ligand and tumor necrosis factor α (TNF-α) also are implicated as secondary mediators of cell death via the inducible nitric oxide synthase pathway.1,4-6
Since TNF-α was found to be elevated in serum and blister fluid in patients with TEN,7,8 medications aimed at decreasing the TNF-α concentration, such as pentoxifylline (PTX) and thalidomide, have been attempted for treatment.9,10 Biologic inhibitors of TNF-α, such as infliximab and etanercept, are novel therapeutic options in the treatment of TEN, as numerous reports document their successful use in the treatment of this disease.11-24 The purpose of this study is to systematically review the current literature on the use of TNF-α antagonists in the treatment of TEN.
A PubMed search of all available articles indexed for MEDLINE using the terms toxic epidermal necrolysis and TNF-alpha and pentoxifylline or thalidomide or infliximab or etanercept or adalimumab was conducted.
Sixteen articles published between 1994 and 2014 were retrieved from PubMed and reviewed.9-24 Fourteen articles were case reports and case series involving the use of TNF-α inhibitors as either monotherapy, second-line agents, or in combination with other medications in the treatment of TEN, providing a total of 28 patients.9,11-23 Two articles were prospective trials, one evaluating the efficacy of thalidomide10 and the other infliximab24 in treating TEN. All studies implemented primary treatment (ie, prompt discontinuation of the suspected medication and aggressive supportive care) in addition to TNF-α inhibition.
The first case report describing the use of an anti–TNF-α inhibitor for TEN was with PTX in 1994.9 Pentoxifylline, a vasoactive drug with immunomodulatory properties including the downregulation of TNF-α synthesis, was used to treat a 26-year-old woman with TEN on phenylhydantoin 15 days following resection of a grade II astrocytoma. The patient initially received intravenous N-acetylcysteine (NAC) (9 g once daily) and S-adenosyl-L-methionine (100 mg once daily) for antioxidant effects. On the second day of treatment, intravenous PTX (900 mg once daily) was added for TNF-α inhibition. Following PTX administration, the investigators reported quick stabilization of the eruption and achievement of reepithelialization after 7 days of therapy. Upon cessation of PTX therapy, a recurrence of generalized erythema occurred, suggesting a relapse of TEN; therefore, PTX was reinitiated for an additional 3 days, and the patient’s skin remained clear.9
The earliest prospective trial we reviewed using anti–TNF-α therapy in TEN occurred in 1998 with thalidomide, a moderate inhibitor of TNF-α.10 In this randomized controlled trial, 22 TEN patients received either a 5-day course of thalidomide (400 mg once daily) or placebo. There was increased mortality in the thalidomide group (10/12 [83.3%]) versus the placebo group (3/10 [30.0%]). Additionally, the plasma TNF-α concentrations in the thalidomide group were higher than the control group. This study was stopped prematurely due to the excess mortality in the thalidomide group.10