My kid had an allergy..we go and the doctor and he refered the kid to specialist dermatologist.they take bloods for food allergy bt the results came no food allergy detection.what can i do now?because my kid everytime she ate something she develops

Keep food diary: Both blood & skin allergy tests will not always identify troublesome foods. They can reveal worrisome triggers to bad allergic reactions but miss food intolerance.I would keep a food diary /calendar. Exclude any food you think may be an issue for 2 weeks then list any issues that occur within 3 days of starting it again. Repeat the process to be sure. This should help.