Hi.. Can understand your concern.. As per your complain soreness and swollen gums can occur due to scratching or injury to the gums when you take hard food items and hard potato chips can do that injury no matter how much precaution you take if they get touched to the palate it can cause injury leading to soreness and mild swelling.. Other thing which you explained it is true that on taking a particular brand of chips there can be certain spices or flavouring agents added to it causing you mild allergic reaction leading to the following symptoms. One more thing you need to consider that if you are taking any particular dip along with the chips any ingredient of the dip can also cause allergy but if not there is something with the chip only. In case of allergy avoidance is the only way to prevent its happening. Hope your query is solved.. If you find the answer helpful please write a positive review and click on find this answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora.