Chronic Immune Thrombocytopenia Purpura Following COVID-19 Vaccination (ChAdOx1 -nCov-19): A Case Report With OneYear Follow-Up.

Background: Immune Thrombocytopenia Purpura (ITP) is a hematological disorder, where its primary cause is unknown. This can be triggered through any secondary underlying diseases or other environmental agents such as drugs, vaccination, natural viral infections etc. After the introduction of COVID-19 vaccines, a 4-fold increase in ITP cases was observed globally. Many of the COVID-19 vaccines such as m-RNA and viral-vector vaccines already demonstrated a cause-effect relationship between the event of ITP and immunization. Case presentation: A 54 year old diabetic patient presented to the hospital with complaints of gum bleeding and fatigue. He was diagnosed with severe ITP following COVID-19 vaccination with a platelet count of 5000 cumm. Initially his condition was considered as idiopathic and the COVID-19 vaccine exposure (13 days prior to the clinical presentation) was not suspected. Later the immunization timeline and onset of the reaction was traced by his hematologist. The patient underwent multiple platelet transfusions and was given corticosteroid therapy. The patient was followed for a period of 1 year and throughout the follow-up period the patient had fluctuating platelets count, especially after tapering steroids. Conclusion: ITP in this case is found to have a consistent causal association to COVID-19 vaccination as per the World Health Organization Causality assessment algorithm and is categorized under vaccine product related reactions. One year follow-up conducted showed that the thrombocytopenia following COVID-19 vaccine may be prolonged.