I myself had an egg allergy/intolerance when I was a baby. I also vomited after eating eggs but didn't have other symptoms (I apparently ruined the new carpets of my parents' friends after we all went and ate ice cream that had eggs in it). I DID grow out of it and love eggs now. I also haven't had any problems with other allergies.
My brother was allergic to anything orange for a time, and he also would get boils after he took a bath (so he took showers from a very early age). Bodies are weird.