Clinical features, treatment, and prognosis of pembrolizumab -induced Stevens-Johnson syndrome / toxic epidermal necrolysis.

The understanding of pembrolizumab-induced Stevens-Johnson syndrome (SJS) /toxic epidermal necrolysis (TEN) primarily derives from case reports, leaving specific clinical features largely unknown. This study aims to investigate the clinical characteristics associated with pembrolizumab-induced SJS/TEN and to encourage the judicious use of pembrolizumab. Retrieve reports on pembrolizumab induced SJS/TEN before September 30, 2024 for retrospective analysis. Twenty-four (57.1%) and 18 (42.9%) patients were enrolled, with a median age of 65 years (range 32, 81). The median time to onset of SJS/TEN was 15 days (range 2, 180), and the median cycle was 1 cycle (range 1, 9). The most prevalent skin symptoms included erythema (66.7%), rash (64.3%), bullae/blisters (50.0%), and epidermal detachment (42.9%). Skin biopsy findings primarily revealed epidermal necrosis (42.9%), keratinocyte necrosis (35.7%), subepidermal bulla/blister (19.0%), and perivascular inflammatory cell infiltration (47.6%). Following the cessation of the drug and subsequent treatment, 85.7% of patients showed symptom improvement, while 14.3% succumbed to the condition. SJS/TEN represents a rare but potentially fatal adverse reaction to pembrolizumab. Clinicians should consider SJS/TEN in patients presenting with fever, erythematous rash, or mucosal involvement. Timely identification and management of SJS/TEN can significantly reduce morbidity and mortality.