I believe that a barrier cream is extremely important, especially if your particular EC is caused by a form of contact dermatitis. The cream will shield your lips from most harmful contaminants in the air around your environment.
The cream that has worked the best for me at this point is Bepanthen. This cream is not sold in the United States to my knowledge so, I bought mine at Amazon.com. Let me tell you, best thing I ever did. I feel like it is really making a difference.