When I was 23, 24, I used to have a really bad runny nose, mucus, tons of acne, reddishness all over. A woman on a bus I took looked at me and said I was lactose intolerant. She said: 'Stop dairy for three days, and all this is going to go away.' I stopped dairy, and sure enough it was gone three days later, never to return except when I get dairy accidentally.