Abstract: Objective: To determine the sensitizing drug in a case of toxic epidermal necrolysis (TEN) possibly caused by osimertinib. Methods: The patient with TEN had previously taken osimertinib mesylate tablets, mosapride citrate tablets, and diclofenac sodium sustained-release capsules before the onset of the disease. To identify the sensitizing drug, the Naranjo score, ALDEN score, lymphocyte transformation test (LTT), and Enzyme-Linked Immunospot Assay (Elispot) were performed. Relevant literature was searched and analyzed for further information. Results: The osimertinib were both 2 points of Naranjo score and ALDEN score, which was the highest score among all used drugs, and the LTT result of osimertinib was positive. A total of 7 cases of TEN caused by osimertinib were reported in the literature. Conclusion: Combining the results of Naranjo score, ALDEN score and LTT, the patient was diagnosed with toxic epidermal necrolysis caused by osimertinib.

Key words: toxic epidermal necrolysis')">">toxic epidermal necrolysis, osimertinib, epidermal growth factor receptor