You can try and eliminate certain foods and products. Do you currently apply anything to your lips?
On top of the allergy testing I think you should find a good dermatologist, as for the inflammation I feel protopic would help a lot with that, if the root cause can not be eliminated (no allergy found) but again that would be at your dermatologists discretion. Your condition is treatable so try not to worry, call the dermatologists office for cancellations.