What Causes Face Itching With Back Rashes And Swelling?

hi, i am a 30 years old man and i have this problem that occurs occasionally. First my face would start to itch, the following morning i would have developed rash on the back of my neck, forehead and a swollen face and eyes. My penis would also show signs of rash. Then after 2-3 days everything disappears. The problem would come again after 7-9 months or maybe a year later. This have been happening for atleast 5-6 years. Please HELP!!!!!