Previously diagnosed or possible high risk of conditions that may be associated with autoimmune thrombocytopenia, for example, HIV, HCV, or other infection; other autoimmune/immunodeficiency disorders (including systemic lupus erythematosus [SLE]); malignancy (eg, lymphoproliferative disorders); recent vaccination

Liver disease (including alcoholic liver cirrhosis)

Drugs (prescription or non-prescription), alcohol abuse, consumption of quinine (tonic water), exposure to environmental toxins

Bone marrow diseases including myelodysplastic syndromes, leukemias, other malignancies, and fibrosis, aplastic anemia, and megaloblastic anemia

Recent transfusions (possibility of posttransfusion purpura) and recent immunizations

Inherited thrombocytopenia: thrombocytopenia-absent radius (TAR) syndrome, radioulnar synostosis, congenital amegakaryocytic thrombocytopenia, Wiskott-Aldrich syndrome, MYH9-related disease, Bernard-Soulier syndrome, type IIB von Willebrand disease