1st April 2022

A mother brings her 2-year-old son to see you – the GP

A mother brings her 2-year-old son to see you – the GP. She is concerned that he bruises easily and is unable to straighten his left knee. He has also been complaining of pain in his knee. His mother said this seemed to come on suddenly. On examination, he has excessive bruising around both knees, and his left knee is swollen and warm to touch. He is apyrexial. On further questioning, the mother mentions that her uncle died when he was a young boy.  

What is the most likely cause of his symptoms? 

Select the SINGLE most appropriate option from the list below. Select ONE option only.