Do you take cold medications and Benadryl on a regular basis?

one of my sisters had bad migraines and even more when she was pregnant, she'd start throwing up after breakfast. She later got tested for allergies and found to be allergic to eggs, even a teaspoon of mayo on a sandwich would trigger her migraines. Had a brother-in-law who was also allergic to eggs and would be sick all day long with headaches.