Atypical Stevens-Johnson syndrome-like reaction in the setting of immune checkpoint inhibition.

Abstract

102 Background: Stevens-Johnson syndrome (SJS) is a rare, life-threatening mucocutaneous toxicity that can occur in patients receiving immune checkpoint inhibitors (ICIs). ICI-induced SJS is scarcely reported in the literature and thus remains poorly understood, particularly regarding features that may distinguish it from classic SJS. Methods: To describe the timing, clinical manifestations, and treatment course of ICI-induced SJS, this multicenter, retrospective study identified seven patients with SJS in the setting of ICI use from January 2011 through May 2019. Results: All seven patients presented initially as benign, limited drug eruptions after a median of 4 ICI cycles (range, 1-7) and 63 days (range, 13-253 days) from ICI initiation. While none of the patients had prior drug allergies, all 7 were receiving new, recently initiated – i.e., within two months – medications at the time of rash onset. Cases demonstrated characteristic histologic findings of SJS, such as epidermal necrosis, and occasional unusual features, including interface dermatitis. All patients responded favorably and rapidly to systemic therapy, primarily intravenous corticosteroids, with near immediate symptomatic resolution and cessation of progressive skin blistering or detachment. Median length of stay was 11 days and no patients died from SJS. Conclusions: Our cohort defines an atypical SJS-like reaction secondary to ICI use, which is distinct from classic SJS in its delayed onset, mild initial presentation, and rare ocular involvement. The association with concomitant medication use suggests a potential mechanism whereby ICIs reduce patient immune tolerance to subsequent drug exposures. Reassuringly, this atypical SJS-like phenomenon exhibits a benign clinical course and favorable response to standard treatments.