ear lobe is a common area or furuncle
or boil or in very simple terms, pimple. since you have already popped the same, make sure that the swelling has completely subsided and the pain is gone. if not then consult a GP and take a course of antibiotic medication. to prevent the same in future, do what you do to prevent pimple, that is:
1. avoid oily food
2. Avoid cosmetics and oils which increase the oil level of your skin or make it moist.
3. while wearing jewelery, make sure you clean them with a cotton swab or better yet with an antibiotic solution.
4. if the problems recurs, consult a dermatologist
or a skin specialist.