Idiopathic thrombocytopenic purpura

1. IDIOPATHIC THROMBOCYTOPENIC PURPURA
DR. M. BABAR AHMED

2. SCENARIO
 A 3 year old child develops bruising and generalized petechial rash, more prominent over his legs.
There is no past or recent history of any infection sore throat etc. There is no hepatosplenomegaly or
lymphadenopathy. There is no significant finding on examination in any system. The CBC shows a platelet
count of 15000/uL rest of the parameters are normal?
 What is the provisional Diagnosis?
 What DD can you think of?

3. EPIDEMIOLOGY
 Incidence is about 8 per 100000 children per year
 Acute ITP is more common in children younger than 10 years of age and the maximum incidence is
between 2-5 years and affects males and females equally usually follows a viral illness
 Chronic ITP is more common in Adolescents and Has a female predominance

4. PATHOGENESIS
 It is usually considered as an autoimmune disorder
 Autoantibodies are formed against glycoproteins gpllb/llla that are expressed on platelet membranes
 The spleen and other organs of the reticuloendothelial system recognize these antibody coated platelets
and lead to their phagocytosis and ultimately destruction
 Some studies also suggest that in addition to, immune mediated destruction, the formation of platelets
is also altered especially in chronic ITP
 On bone marrow examination the number of megakaryocytes is increased or is normal, but the plasma
levels of thrombopoietin, which actually is the measure of proliferation and maturation of
megakaryocytes is decreased.
 Some studies suggest association with viral infections such as EBV, HIV and even post H.Pylori bacterial
infection
 Hence the name idiopathic as there is no clear cause known to this disease

5. ACUTE ITP
 It is the most common bleeding disorder of Childhood
 It may follow infections such as Rubella, Varicella, Measles, or EBV.

6. CHRONIC ITP
 It is defined as persistence of thrombocytopenia for more than one year from initial presentation of
signs and symptoms
 It usually results from immune clearance of Antibody coated platelets
 The spleen is the major culprit as it forms antibodies and sequesters and clears the coated and formed
platelets

7. CLINICAL PRESENTATION
 It usually presents in a previously healthy child with sudden onset of formation of petechiae, purpura or
easy bruising.
 Bleeding form mucosal surfaces such as the nose, mouth, or gum is seen in 1/3rd of the patients
 In Acute ITP the onset symptoms be preceded by an acute viral infection.
 Except for bleeding other examination findings are usually insignificant.
 Splenomegaly, Lymphadenopathy, and bone pains are usualy rare and not present

8. DIAGNOSIS
 On CBC the key to diagnosis is the presence of low platelet count <50,000/mm3 and often
<10,000/mm3
 All of the cell lines are usually normal for all age groups
 In about 15% of the patients mild normocytic normochromic anemia may be present because of mild
bleeding
 The PT and APTT are always normal
 Bleeding Time is always prolonged
 Platelet associated IgG IgM may be demonstrated in serum

9. DIFFERENTIALS
 Leukemia can be differentiated on the basis of elevated WBC count, anemia, presence of blast cells in
smear, and there may be hepatosplenomegaly along with lymphadenopathy
 Aplastic anemia in this almost all of the cell lines are depleted
 Lymphoma usually has cervical lymphadenopathy

10. MANAGEMENT
 Acute ITP can be managed with supportive measures, many children require no treatment, only
restricting activity and trauma prevention can be the best line of action
 Avoiding drugs such as antiplatelets e.g. aspirin, clopidogrel, prasugrel, and sulfonamides can be helpful
 In emergency situations a mega kit of platelets can be transfused but is rapidly destroyed

11. PHARMACOLOGICAL TREATMENT
 As per the American society of Hematology Guidelines a single dose of IVIG @0.8-1g/kg/day or a short
course of steroids should be the initial pharmacological treatment
 It is usually fruitful and raises the platelet count rapidly
 Steroids are given at a dose of 1-4mg/kg/day
 A short course can be continued upto 2 weeks and then it needs to be tapered off

12. MANAGEMENT OF CHRONIC ITP
 The goal of management in chronic disease is also to minimize the risk of bleeding
 The patient should be directed to avoid activities that increase the risk of a bleed
 Patient should also be evaluated for other autoimmune disorders, as their might be an underlying
autoimmune disease
 Pharmacological treatment is identical involving the use of IVIG and steroids

13. SPLENECTOMY
 For IVIG and steroid resistant patients, Splenectomy induces long term remission, but it should be
considered if the patient is thrombocytopenic for one year
 The risk of infection is increased after splenectomy, especially in children, therefore the procedure should
be postponed until the child is of 5 years of age
 Administration of vaccinations especially against encapsulated organisms should be done prior to the
procedure prophylactic penicillin should also be considered

14. MCQS
 A 26 year old female presents in the ER with previous history of formation of rash on legs and formation
of blood blisters on her tongue. This time a similar event has taken place after almost 3 years following
an attack of acute pharyngitis, on examination she has hepatosplenomegaly, and gives a long history of
formation of purpura on and off, and has history of clinically significant bleeding after small injuries. The
CBC shows a moderately decreased platelet count all other indices are insignificant.
How will you initially start the treatment of this patient
1. IVIG only
2. IVIG and prednisolone
3. IV steroids
4. Transfusion of FFPs

15.  What is the most common cause of acute onset of thrombocytopenia in an otherwise well child ?
a. SLE
b. Wiskott-Aldrich syndrome
c. HIV
d. ( autoimmune )ITP