WBR0962

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Author [[PageAuthor::Mugilan Poongkunran M.B.B.S [1]]]
Exam Type ExamType::USMLE Step 3
Main Category MainCategory::Primary Care Office
Sub Category SubCategory::Hematology
Prompt [[Prompt::A 24 year old male comes to your office for regular health check up as he is joining a new job. He has no symptoms and his past history is insignificant. His family history is positive for hypertension in both his parents. He is sexually active and uses contraception. His vitals are temperature: 36.7 C, blood pressure: 120/80 mmHg, pulse: 90/min and respirations: 15/min. All system examinations are normal. His laboratory values are as follows :

Blood glucose : 98 g/dl Hb : 13 g/dl RBC’s : 2.5 million/cmm WBC’s : 6000/cmm Platelets : 35,000/cmm Neutrophils : 60 % Lymphocytes : 32 % MCV : 85 fl ESR : 15mm/hr PT : 13 sec (N 11-15 sec) APTT : 30 sec (N 25-40 sec) BT : 9 min (N 2-7 min) Serum creatinine : 1.2 mg/dl Serum calcium : 9 g/dl

Which of the following is the best next step in the management of this patient?]]

Answer A AnswerA::I.V platelet transfusion
Answer A Explanation [[AnswerAExp:: Incorrect  : Platelet transfusion is not normally recommended and is usually unsuccessful in raising a patient's platelet count. This is because the underlying autoimmune mechanism that destroyed the patient's platelets to begin with will also destroy donor platelets. An exception to this rule is when a patient is bleeding profusely, when transfusion of platelets can quickly form a platelet plug to stop bleeding, a life-threatening hemorrhage. Intravenous immunoglobulin administration, with the platelet transfusion, may improve their survival.]]
Answer B AnswerB::I.V immunoglobulin
Answer B Explanation [[AnswerBExp:: Incorrect  : The platelet count can be temporarily supported by the use of intravenous immune globulin (IVIG) or by anti-Rh(D) (Rho(D) immune globulin, anti-D, WinRho) in patients whose red cells are Rh(D) positive and who have not had a splenectomy. Both of these agents increase the platelet count in most patients with ITP, including patients who have not responded to corticosteroids, within several days, with an effect that may last for several weeks]]
Answer C AnswerC::Splenectomy
Answer C Explanation [[AnswerCExp:: Incorrect  : Splenectomy offers a 2nd line treatment for those who fail steroids. The criteria for surgery are severe thrombocytopenia (<10,000), high risk of bleeding or the requirement of frequent steroids/IVIgG/anti-D treatment to maintain an adequate platelet count.]]
Answer D AnswerD::Observation and follow-up
Answer D Explanation AnswerDExp::''' Correct ''' : Avoid unnecessary treatment of asymptomatic patients with mild to moderate thrombocytopenia (ie, a platelet count greater than 30,000/microL).
Answer E AnswerE::I.V glucocorticoids
Answer E Explanation [[AnswerEExp:: Incorrect  : Adults with severe thrombocytopenia (platelet count below 30,000/microL) at the time of diagnosis are treated, most often with glucocorticoids.]]
Right Answer RightAnswer::D
Explanation [[Explanation::Idiopathic thrombocytopenic purpura (ITP) is the condition of having a low platelet count (thrombocytopenia) of no known cause (idiopathic). As most causes appear to be related to antibodies against platelets, it is also known as immune thrombocytopenic purpura. Most often these antibodies are against platelet membrane glycoproteins IIb-IIIa or Ib-IX, and are of the IgG type. The cause of ITP is thought to be related to chronic infections such as HIV, hepatitis C and H. Pylori. The mechanism involved is thought to be molecular mimicry, that is, antibody is formed against the infection and this cross-reacts with platelets. The antibodies also appear to damage megakaryocytes, preventing them from releasing platelets. The pathogenesis of ITP is presumed to be related to increased platelet destruction along with inhibition of platelet production via the production of specific autoantibodies. Although most cases are asymptomatic, very low platelet counts can lead to a bleeding diathesis and purpura. Adults with severe thrombocytopenia (ie, a platelet count below 30,000/microL) at the time of diagnosis are almost always treated even if they are asymptomatic or have only minor bleeding symptoms, because the course of the disease and the risk for future bleeding cannot be known. Avoid unnecessary treatment of asymptomatic patients with mild to moderate thrombocytopenia (ie, a platelet count greater than 30,000/microL).

Educational Objective:
References: ]]

Approved Approved::Yes
Keyword WBRKeyword::ITP
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