Variable presentation of thrombocytopenia in Graves' disease

An association between thrombocytopenia and thyrotoxicosis has been reported but its mechanism is unclear. We describe five patients in whom thrombocytopenia accompanied Graves' disease. The thrombocytopenia resembled idiopathic thrombocytopenic purpura and responded to prednisone therapy in cases 1 and 2. In case 3, thrombocytopenia remitted with treatment of the thyrotoxicosis, while, in case 4, remission occurred despite persistent hyperthyroidism. In case 5, thrombocytopenia persisted despite correction of the hyperthyroidism but remained clinically insignificant. We conclude that there is a clear association between the two conditions but the clinical patterns of presentation and pathogenesis seem heterogenous. This variability must be considered during management.