Medical Conditions - Onion Allergy

People allergic to onions can exhibit the symptoms of allergic reactions soon after smelling, eating, or touching the onion or a few hours later. Allergic reactions can range from mild to severe, like skin itching and rash, nose block, shortness of breath, nausea, diarrhea, vomiting, etc. Once the onion or its contact is eliminated from the body, the symptoms resolve. If they persist, seek a doctor's help.