IgG testing is NOT the way that allergy, sensitivity or intolerance is tested or measured. If you really need to figure out if it’s an allergy, you either do a specific IgE test for the SINGLE thing you suspect of causing the symptoms, do a skin prick test, do a CAST test if you suspect a non-IgE type allergic reaction, or a (double blind placebo controlled) food challenge. Large panels of tests, even panels of IgE tests have very little value in diagnosing allergies. https://www.aaaai.org/conditions-and-treatments/library/allergy-library/IgG-food-test
The mentioned issue around mucus is also questionable. Egg allergy (and yes, it’s almost always the white, because it’s the PROTEIN part) is a serious condition, not just a minor inconvenience. It’s also quite rare in adults. https://adc.bmj.com/content/archdischild/104/1/91.full.pdf
Unfortunately most of the allergy symptoms adults experience, and especially the upper airway symptoms you’re mentioning, are due to aeroallergens or direct irritants (NOT so much food items) and apart from modifying your environment or exposure to these allergens and taking your specific meds, there’s not much to do but grin and bear it. It is just not possible to have all patients COMPLETELY symptom free.