What Causes Swelling Of Nose And Lips?

My nephew, 14 years old, has been picking his nose for years, with increasingly worrying effects. His nose swells up, his lips are very swollen and protrude almost immediately, and his acne flares up, within hours. We only realised how bad it was when a dermatologist, who thought his skin was strongly inlaced days after UV treatment spoke of putting him on tablets, which have strong side effects. I think my nephew was so horrified that he stopped picking for a few days and we were utterly astonished at the change to his features and the fact that the acne seemed to disappear. We are very concerned about longterm effects and possibly lasting damage.