Rationale:Reactive cutaneous capillary endothelial proliferation (RCCEP) is the most prevalent immune-related adverse event observed in patients undergoing camrelizumab treatment, and there is a lack of effective therapeutic strategies. Thalidomide (THD) has anti-inflammatory, immunomodulatory, antiangiogenic, and antitumor properties, which have led to its use in various autoimmune diseases, hematological malignancies, solid tumors, and other disorders.Patient concerns:A 52-year-old male patient with lung cancer developed vascular moles on his face, neck, and back after 3 cycles of chemotherapy comprising pemetrexed and carboplatin combined with camrelizumab immunotherapy. The moles ranged in size (0.1–1.2 cm) and were red or red-black, appearing on the skin’s surface. The patient was advised to avoid scratching or friction, continue monitoring, and apply Yunnan Baiyao powder if a papule ruptured. After the third treatment cycle, papules on the patient’s face, particularly an eyelid vascular mole, ulcerated, causing significant psychological distress.Diagnosis:RCCEP induced by camrelizumab was considered.Interventions:The patient received 50 mg of THD in the morning and 100 mg in the evening.Outcomes:The vascular nevus began to shrivel after 1 week and started disappearing after 2 weeks of THD treatment. After 3 THD treatment courses, RCCEP was alleviated without recurrence, allowing the patient to successfully complete camrelizumab treatment.Lessons:During treatment with camrelizumab, if a patient develops moderate or severe RCCEP, and local therapy or anti-infective therapies prove insufficient, THD may be considered as a potential treatment option to improve RCCEP symptoms.