Rationale:Immune-related adverse events are occasionally reported in Sintilimab treatment. This study reports a forward and reverse swelling case along the vein after infusion of Sintilimab. At present, swelling along the vascular direction during peripheral infusion are limitedly reported at home and abroad, especially when choosing a vein with thick, elastic, and good blood return.Patient concerns:A 56-year-old male who suffered from esophageal cancer and liver cancer and received albumin-bound paclitaxel and nedaplatin chemotherapy in combination with Sintilimab immunotherapy appeared swelling along the vessel after infusion of Sintilimab. The patient was punctured 3 times.Diagnoses:Sintilimab-induced vascular edema may be a side effect resulted from a combination of variables such as relatively poor vascular function of the patient, chemical extravasation, allergic skin reactions, venous valves, vascular intima, and diameter stenosis. Sintilimab rarely causes vascular edema only when drug allergic reaction is the underlying factor. As only a few cases of vascular edema caused by Sintilimab have been reported, causes to such a drug-induced vascular edema remained unclear.Interventions:The swelling was controlled by an intravenous specialist nurse according to delayed extravasation treatment and the doctor anti-allergy treatment, but the uncertainty of repeated puncture and symptom diagnosis caused pain and anxiety to the patient and his family.Outcomes:The symptom of swelling was gradually relieved after the anti-allergic treatment. The patient completed the following drug infusion without discomfort after the third puncture. When the patient was discharged the next day, swelling in his both hands disappeared, and the patient had no anxiety or discomfort.Lessons:The side effects of immunotherapy may accumulate over time. Early identification and appropriate nursing management are the keys to minimizing patients’ pain and anxiety. To effectively treat symptoms, nurses could benefit from quickly identifying the source of swelling.