I have periodicly swelling of lips , sometimes it also radiates to my cheak and now notice a swelling patch on my back , it doesnt seem to be assosiated with any foods never had allergies before, could it be a medication side effect, my dr. dosent seem to think it would be and he has no suggestions. It seems to happen 2-3 times per week, nothing seems to trigger it. We did go to Mexico this winter and seems to be there since then, could it be a parasite or something, truly puzzled any suggestions?