Immune Thrombocytopenic Purpura (ITP)

Question 1

Define Immune/Idiopathic thrombocytopenia (ITP)

Answer 1

Autoimmune disease characterized by a low platelet count, purpura, & hemorrhagic episodes caused by antiplatelet autoantibodies.

Question 2

Thrombocytopenia occurs in ITP due to?

Answer 2

• results from shortened life span of platelets in the circulation + incomplete compensation by increased platelet production by bone marrow megakaryocytes.

Question 3

Pic slide 4 - Peripheral blood smear in a ITP patient

Answer 3

• decreased number of platelets
• normal appearing neutrophil
• normal appearing RBCs

Question 4

True or False

ITP is diagnosed by excluding other diseases in peripheral blood smear.

Answer 4

True

Question 5

Signs & Symptoms of ITP

Answer 5

• bleeding tendency
• easy bruising
• purpura
• extravasation of blood capillaries into skin
• intracranial hemorrhage in children (0.5 - 1%) when platelet count drops below 10 x 10(9)

Question 6

True or False

The severity of symptoms of the viral illness doesn’t correlate with the degree of thrombocytopenia.

Answer 6

True

Question 7

Thrombocytopenia is a recognized complication most commonly associated with?

Answer 7

a viral URTI

Question 8

Transient thrombocytopenia has been reported in association with recent immunization, especially with ________ vaccines.

Answer 8

attenuated live-virus

Question 9

Drug induced thrombocytopenia

Answer 9

• history of all prescription & over-the-counter medications is required to exclude drug-related thrombocytopenia.
• 573 drugs (out of 1444 drugs) have a statistically significant reporting association with thrombocytopenia.

Question 10

Criteria for the diagnosis of Drug induced thrombocytopenia

Answer 10

• development of the low platelet count should exhibit a strict temporal relationship with the initiation of the medication .
• platelet count should recover when the offending medication is discontinued.
• the likelihood of drug-induced thrombocytopenia should be greater than any other plausible cause.
• Ideally, in vitro evidence of drug-dependent antibody formation should exist .

Question 11

Drugs associated with drug purpura

Answer 11

• Heparin
• Antibiotics (e.g. cephalosporins)
• Analgesics
• Diuretics
• Acute & Chronic alcohol consumption

Question 12

Human immunodeficiency virus (HIV) infection

Answer 12

• thrombocytopenia may occur during the acute retroviral syndrome coincident with fever, rash & sore throat.
• HIV-related thrombocytopenia is particularly likely to occur in people who abuse drugs.

Question 13

HIV-related thrombocytopenia is particularly likely to occur in people who…

Answer 13

abuse drugs

Question 14

Physical examination for ITP should focus on…

Answer 14

• findings that suggest that thrombocytopenia is a complication from another disease.
• internal bleeding signs
• findings suggestive of intracranial hemorrhage

Question 15

Initial impression of the severity of ITP is formed by examining the skin & mucous membranes as follows…

Answer 15

• Mild = petechiae over the ankles or on the back.
• Serious complication:
  a) widespread petechiae & ecchymoses
  b) blood oozing from a venipuncture site
  c) gingival bleeding
  d) hemorrhagic bullae (fluid filled blister on skin)
  e) petechiae:
• may be observed under & distal to the area where the cuff was placed & inflated in a patient who has just measured their BP.
• may be induced by ECG leads

Question 16

Findings suggestive of intracranial hemorrhage

Answer 16

• headache
• blurred vision
• somnolence
• loss of consciousness
• hypertension & bradycardia (↑ intracranial pressure)