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OVERVIEW
This page is dedicated to organizing various examples of standardized exam questions whose answer is immune thrombocytopenia purpura (ITP). While this may seem a odd practice, it is useful to see multiple examples of how ITP will be characterized on standardized exams (namely the boards and the shelf exams). This page is not meant to be used as a traditional question bank (as all of the answers will be the same), however seeing the classic “test” characterization for a disease is quite valuable.
KEY CHARACTERISTICS OF THIS CONDITION (ON EXAMS)
When it comes to standardized exams, each condition has its own “code” marked by key buzzwords, lab findings, clues, etc. If you are well versed in this code you will be able to more quickly identify the condition that is being discussed, and get the right answer on the exam you are taking. Below is the “code” for ITP.
- Isolated thrombocytopenia: no other coagulopathy should be present (PT and PTT times should be relatively normal)
- Normal blood smear: unlike other thrombocytopenias that have signs of microangiopathic anemia
- Increased megakaryocytes can be seen on a bone marrow biopsy/aspirate (VERY SPECIFIC)
QUESTION EXAMPLES
Question # 1
A previously healthy 37‐year-old woman comes to the physician because of bruising on her arms and abdomen for 3 weeks. She takes ibuprofen as needed for occasional headaches. Her temperature is 363°C (98.4”F). Examination shows ecchymoses over the upper extremities and trunk. The lungs are clear to auscultation. Cardiac and abdominal examinations show no abnormalities. Laboratory studies show:
- Hemoglobin: 12.9 g/dL
- Leukocyte count: 6500/mm³
- Platelet count: 44,000/mm³***
- Bleeding time: 11 min
- PT: 15 sec (INR 1.4)
A bone marrow aspirate is conducted and shows an increased presence of megakaryocytes. What is the likely diagnosis?
Explanation # 1
Low platelets + no other coagulopathy + magakaryocytes increased in bone marrow = ITP
TESTABLE FACTS ABOUT THIS CONDITION (BEYOND ITS IDENTIFICATION)
Many questions on standardized exams go beyond simply recognizing the underlying condition. Often there are specific testable facts regarding some aspect of the disease’s pathophysiology/management/clincial implications that are commonly asked. Some of these are listed below:
- Cause: autoantibodies that bind common antigens (such as GPIIb/IIIa) on platelets leading to their destruction
- First line therapy:
- Corticosteroids (prednisone/dexamethasone)
- Second line therapy:
- Splenectomy: reserved typically when all else fails/there are no other practical treatment options.
Page Updated: 01.22.2017