Final answer:
Common foods responsible for the majority of food allergies are peanuts, milk, eggs, certain grains, and shellfish. These can trigger symptoms from itching to anaphylaxis, a severe reaction.
Step-by-step explanation:
The foods responsible for the majority of food allergies include peanuts, milk, eggs, certain grains like wheat, and shellfish. These foods can cause the immune system to overreact as if they were harmful substances, leading to symptoms such as itching, swelling, vomiting, diarrhea, and in severe cases, anaphylaxis. Anaphylaxis is a potentially life-threatening reaction that requires immediate emergency medical treatment.