Chronic Immune Thrombocytopenia and Hashimoto's Hypothyroidism in an Adolescent: Presentation and Implications

Immune thrombocytopenia (ITP) is a disorder characterized by immune-mediated destruction of thrombocytes leading to peripheral blood platelet count of <100 × 10^9/L. Primary ITP is a terminology used in the absence of other causes or disorders that may be associated with thrombocytopenia, i.e., isolated thrombocytopenia. The term secondary ITP is used if such diseases coexist. We present here a case of a 14-year-old female diagnosed with immune thrombocytopenia. When her evaluation was not strongly supportive of primary ITP, she was screened and proved to have a concomitant Hashimoto thyroiditis. Contrary to the popular belief about secondary ITP in adult population, treatment of our patient's hypothyroidism did not improve her platelet's count, and the patient needed multiple immunosuppressive medications to improve her condition.