Idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura, also known as autoimmune thrombocytopenic purpura, is a disease characterised by IgG autoantibody-mediated platelet destruction resulting in a low platelet count of 150 x10 9 or less. It is a diagnosis made by excluding other causes of thrombocytopenia.

In children ITP tends to occur after viral infections and be self-limiting. In adults it tends to last longer and often follows a chronic course.

Treatment is only needed if the patient is symptomatic or the platelets are <20.

• First line = oral prednisolone - 80% respond
• If no response in 3 months --> splenectomy – curative for 2/3s of patients 
• Other options include IV IG or immunosupressive drugs. 

Small print gem: Evan's syndrome = ITP +AIHA.

References:

Cines, D. and Bussel, J. How I treat idiopathic thrombocytopenic purpura (ITP). Blood. 2005; 106(7): 2244-2251.

Rodeghiero, F. Idiopathic thrombocytopenic purpura: an old disease revisited in the era of evidence-based medicine. Haematologica. 2003; 88(10): 1081-1087.