Bump behind ear after scratching

[chrisi2009]

Hi,havent been on here for a while because my dads passed away.I suffer with hayfever and exema,well today behind my ear it became very itchy so i scratched it,and a bump formed,it seems to have gone down now.Can anyone tell me what the bump is?

[pd]

Probably a lymph node. They can pop up if you poke/scratch at them.