Management of Refractory Gingival Bleeding During Periodontal Therapy in Vaccine-Associated Immune Thrombocytopenia: A Case Report.

BACKGROUND: Secondary immune thrombocytopenia (SITP) has been rarely reported following mRNA COVID-19 vaccination. Oral manifestations such as gingival bleeding remain underrecognized in dental practice. CASE PRESENTATION: A 58-year-old woman developed extensive ecchymoses, blood-tinged sputum, and spontaneous gingival bleeding approximately 2 weeks after receiving the second dose of the mRNA-1273 COVID-19 vaccine. Laboratory testing revealed severe isolated thrombocytopenia, while coagulation parameters, D-dimer, and fibrinogen levels were within normal limits. After exclusion of other identifiable causes, she was diagnosed with suspected SITP temporally associated with COVID-19 vaccination. Initial treatment with dexamethasone resulted in an insufficient platelet response; therefore, intravenous immunoglobulin was administered, leading to platelet recovery. During the subsequent periodontal scaling, however, profuse gingival bleeding occurred despite a platelet count exceeding 50 × 103/µL. Conventional local hemostatic measures, including pressure application and retraction paste, were unsuccessful. Fibrin glue was then applied, resulting in immediate hemostasis without recurrent bleeding during follow-up. CONCLUSION: This case highlights the importance of recognizing vaccine-associated SITP in dentistry and demonstrates fibrin glue as an effective adjunctive hemostatic measure when conventional approaches are insufficient.