TOXIC EPIDERMAL NECROLYSIS IN A PATIENT WITH GRAFT-VERSUS-HOST DISEASE

Abstract

<h3>Introduction</h3> Toxic epidermal necrolysis (TEN) is a type 4 hypersensitivity reaction leading to extensive skin detachment. TEN occurs 1-3 weeks after offending drug exposure and shares clinical similarities with grade IV graft-versus-host disease (GVHD). We present a case of TEN in a patient with previously diagnosed GVHD, with suspecting culprit agents being oxacillin or oral vancomycin. <h3>Case Description</h3> A 59-year-old man with a history of primary myelofibrosis status-post allogeneic stem-cell transplant complicated by GVHD was evaluated for new-onset desquamative rash. He initially presented with MSSA sepsis, for which oxacillin was administered. His course was complicated by C. difficile colitis requiring oral vancomycin. The patient's rash involved 80% body surface area with tense bullae and denuded skin, Asboe-Hansen sign positive. He had leukopenia to 0.9 and his creatinine peaked at 4.0. Biopsy of this new eruption revealed bullous epidermal necrolytic dermatosis with pustulosis and notable absence of prior cellular infiltration, favoring TEN. His SCORTEN score was 4. He received supportive care including burn unit transfer, but was transitioned to comofort measures shortly thereafter. <h3>Discussion</h3> This case poses with two diagnostic challenges. First, the clinical overlap between grade IV GVHD and TEN highlights the diagnostic utility of biopsy which favored TEN as the etiology of this new eruption versus another flare of cutaneous GVHD. The proper diagnosis is important to direct care and discontinue implicated drugs. Second, while oxacillin seemed the most likely culprit, consideration was give to oral vancomycin as well, given his severe intestinal inflammation making systemic absorption possible.