Pembrolizumab-induced autoimmune Stevens-Johnson syndrome/toxic epidermal necrolysis with myositis and myocarditis in a patient with esophagogastric junction carcinoma: a case report

Immune checkpoint inhibitors (ICIs) have significantly improved outcomes for cancer patients. With the widespread clinical application of ICIs, their adverse reactions have gradually been recognized. The side effects of ICIs are generally less severe than those of chemotherapy. However, some adverse events with ICIs can be life-threatening. Fatal adverse events require a deep understanding and vigilance. Here, we report the case of a 69-year-old patient with esophagogastric junction carcinoma who experienced multiple immune-related adverse events, including Stevens-Johnson syndrome/toxic epidermal necrolysis, myositis, myocarditis, and liver toxicity, after receiving pembrolizumab. The patient experienced skin rash, bilateral ptosis, limb weakness, and shortness of breath. The symptoms progressed rapidly. Following treatment with methylprednisolone, intravenous immunoglobulin, and plasmapheresis, the patient recovered well. No tracheal intubation or tracheotomy was required owing to the timely and effective treatment. From this case, it can be seen that severe skin rash is an important indication of abnormal immune status and an early warning sign of subsequent multiple-organ involvement. As the most dangerous adverse event, myocarditis is closely related to the patient's prognosis. Severe irAEs appear early, progress rapidly, and involve multiple systems and organs, resulting in a high fatality rate. Early recognition and high-dose corticosteroids are key to successful treatment of such patients.