Bruising, Petechiae, Menorrhagia (432/1700)

A 35yo woman has had bruising and petechiae for a week. She has also had recent menorrhagia
but is otherwise well. Blood: Hgb=11.1, WBC=6.3, Plt=14. What is the single most likely dx?
a. Acute leukemia
b. Aplastic anemia
c. HIV infection
d. ITP
e. SLE


























answer: D

Acute immune thrombocytopenia

ITP is caused by IgG autoimmune antibody to platelet cell membrane antigens leading to platelet destruction in the spleen and liver.

Presentation

• Most present between ages of 2 and 5yrs, but can occur at any age.

• 60% have preceding viral infection, e.g. upper respiratory tract infection

(URTI).

• Bruising, purpura, petechiae, mucosal bleeding, menorrhagia.

• Intracranial bleeds very rare (< 0.5%); often associated with trauma.

• Physical examination otherwise usually normal, e.g. no splenomegaly.

Investigation

• FBC: platelet count low, commonly platelet size increased due to compensatory megakaryocytosis. Otherwise FBC is usually normal.

• Testing for platelet antibodies is not clinically useful.

• Bone marrow in ITP normal, but striking increase in megakaryocytes.

Generally, bone marrow aspirate not indicated if the child is otherwise well, unless concurrent pancytopenia, hepatosplenomegaly, lymphadenopathy, or abnormally-increased blasts on FBC suggesting alternative diagnosis, e.g. aplastic anaemia, acute leukaemia, SLE (adolescent girls) or bone marrow failure syndrome.