(BMJ)—A 56-yo woman w/ no PMHx and on no meds presented w/ a 2-day hx of multiple painless, violet hemorrhagic lesions in her mouth, along w/ gingival bleeding. Exam: hemorrhagic lesions in mouth, chest, and arms; otherwise normal. Labs: WBC, Hgb, coagulation panel all WNL; platelets = 0. What is the dx?
Thrombotic thrombocytopenic purpura
Systemic lupus erythematosus
Hypersplenism
Myelodysplastic syndrome
Immune thrombocytopenic purpura
You are correct. Immune thrombocytopenic purpura (ITP) is a rare disorder characterized by a low platelet count (<100×109/L) caused by increased platelet destruction and decreased platelet production, which result in easy bruising and excessive bleeding. The hallmark presentation is mucocutaneous bleeding. Other causes of bleeding and low platelets should be excluded. Additional testing for hep C and HIV is recommended for all adult pts, as both can be assoc w/ ITP. This pt was treated w/ IV methylprednisolone x7 days, and reached a platelet count of 7×109/L. However, 4 days after the initial tx, her platelets decreased to 3×109/L. She received a transfusion of 30×109/L platelets and prednisone. She left the hospital w/ a platelet count of 74 ×109/L but continued to report dizziness and fatigue. She was later started on danazol, which raised the platelet count to 300×109/L.

BMJ 2017;359:j4476