1. I don't think so. There were a couple other people on the forums that were indians that had this problem.
2+3. Might have a correlation with stress and/or Depression I'd say.
4. I think 15-25 would be the age groups where most people get this condition. I've heard of one person who has has this condition for over 40 years though. I myself have had EC since I was 10 or younger.