Causes of Thrombocytopenia (Impaired Production (Toxins - Chemotherapy…
Causes of Thrombocytopenia
Excessive Destruction or Consumption
AI - Immune Thrombocytopenic Purpura
Immune destruction of platelets.
Antibody coated platelets removed following binding to Fc receptors on macrophages.
ITP in Children
Most common 2-6 yrs old.
Mucocutaneous bleeding - brushing teeth, epistaxis, GI.
May be a history of recent viral infection - VZV, measles.
Bleeding may be severe, but life-threatening haemorrhage rare.
ITP in Adults
Less acute than in children.
Characteristically seen in women and may be associated with other AI disease - SLE, thyroid and AI haemolytic anaemia.
Also seen in patients with CLL and solid tumours and those with HIV.
Platelet autoantibodies found in 60-70% of patients. These usually have specificity for platelet membrane glycoproteins IIb/IIIa and/or Ib.
Major haemorrhage rare - only seen in patients with severe thrombocytopenia.
Easy bruising, purpura, epistaxis and menorrhagia common.
Splenomegaly rare. Examination normal other than evidence of bleeding.
Toxins - Chemotherapy & Radiotherapy
Deficiencies - B12 & Folate