What Causes Severe Itching On Face, Neck And Hands On Intake Of Alcohol?

Hello, I used to drink alcohol and caffeine daily but in small amount, and I have stopped taken them to do a cleanse for 8weeks. No alcohol no caffeine even no chocolate. My skin was glowing and I felt very healthy. And now I m done with the cleanse and had a beer, immediately my skin (face, neck, hands and forearms) started to itch really badly. Got small red bumps and it s really itchy. What do you think this is? More drink It gets worse and I can t stand it on the second day of being off cleanse normal again. Any suggestion would be much appreciated... Thank you so much