My mom has allergies to car fumes? Random Headaches, sore throats, stinging eyes, numb lips

My mom has a problem that started happening 6 years ago, supposedly every time a car drives or certain type of fume I dunno she says she gets stinging/burning eyes, a sore throat, numb lips, and sometimes a headache she thinks it could be car fumes or something but shes not sure because sometimes when shes outside driving she doesn't get it, but it may be certain types of car fume I dunno. She's went to doctors and they don't know what it is. It also might be food related were really not sure but she feels bad after eating milk products bread and stuff too, but even when she doesn't eat all these she gets it err any idea what it is or does anybody else have something like this?

short version: Mom gets random headaches+sore throats+stinging eyes+numb lips. Were not sure what's causing it.