This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Anatomy
Normal platelet count is found in 
Select and explain. 
A. Wiskott Aldrich syndrome, B. Henoch schonlein purpura, C. Immune thrombocytopenia, D. Dengue fever
B: Henoch schonlein purpura
Answer: B: Henoch schonlein purpura 
Explanation: Ref Robbins 9/e p526_527 ;8/e p666;7/e p986-987 All other options have decreased platelet count except henoch schonlein purpura .though it has the name purpura ,but the platelet count in this condition is normal.The skin manifestations in HSP are due to small vessel vasculitis