What Causes Episodes Of Severe Headaches In A Child?

My child 3 yrs old suddenly complaint of 2 attacks of severe frontal headache and asked me and his mother to put the palm of our hand and press firmly on the forehead and he stops crying after giving hem a NSTAIDs suppository as i am a physician, since 2 weeks there was a history of mild epistaxis. I am worry because he had a surgical operation for arachnoid cyst since 2 years without any complications allover all the previous time