IntroductionImmune checkpoint inhibitors (ICIs) are human-derived monoclonal antibodies that enhance the anti-tumor immune response of T cells by inhibiting the the programmed cell death-1(PD-1)/programmed death-ligand-1 (PD-L1) pathway, thus producing anti-tumor immune effects. Tirelizumab is a PD-1 antibody inhibitor that has been shown to be effective in combination with chemotherapy for the treatment of squamous cell lung cancer, however, the subsequent immunotherapy-related adverse events (irAEs) have also been widely observed. It has been reported that among patients receiving anti-PD-1 / PD-L1 therapy, about 70 % had at least one irAE, 10 % had severe irAEs, and 0. 5 % had fatal irAEs [1].Stevens-Johnson syndrome (SJS) /toxic epidermal necrolysis(TEN) is a severe type of pleomorphic erythema and a rare adverse mucocutaneous reaction with a mortality rate of up to 50%[2-3]. The body surface area of the skin (BSA) is the main criterion to distinguish SJS and TEN: BSA<10% is classified as SJS, BSA>30% is classified as TEN, and BSA in between is classified as overlapping type SJS/TEN[4]. The main clinical manifestations of this disease are skin blisters, bullae, epidermal exfoliation, mucosal erosion, etc., and in severe cases, there are systemic poisoning symptoms and different degrees of involvement of internal organs[5]. Because of the difficulty in conducting randomized controlled trials in patients with such critical diseases, the standardized treatment of SJS/TEN is a major clinical challenge. The mainstream treatment measures include immediate discontinuation of suspected allergenic drugs, wound care and drug therapy. Although systemic application of glucocorticoids is currently the most common treatment method, some studies have shown that the use of high-dose glucocorticoids increases the risk of complications[6]. Other treatments such as intravenous immunoglobulin (IVIG), immunosuppressants, plasma exchange, etc., although clinically found to improve the condition to a certain extent, but there is no definite study to prove that it can effectively reduce the mortality of the disease [7].Therefore, there is an urgent need for new and effective treatments to improve the prognosis of the disease. In this report, we described the case of a patient with lung squamous cell carcinoma in whom multiple immune-related adverse events were induced by Tirelizumab.