Symptoms usually start as soon as a few minutes after eating a food and as long as two hours after. In some cases, after the first symptoms go away, a second wave of symptoms comes back one to four hours later (or sometimes even longer). This second wave is called a biphasic reaction.
Food allergies happen when the immune system – the body's defense against infection – mistakenly treats proteins found in food as a threat. As a result, a number of chemicals are released. It's these chemicals that cause the symptoms of an allergic reaction.
- Tingling or itching in the mouth.
- Hives, itching or eczema.
- Swelling of the lips, face, tongue and throat or other parts of the body.
- Wheezing, nasal congestion or trouble breathing.
- Abdominal pain, diarrhea, nausea or vomiting.
- Dizziness, lightheadedness or fainting.
- Milk (mostly in children)
- Tree nuts, like walnuts, almonds, pine nuts, brazil nuts, and pecans.
- Fish (mostly in adults)
- Shellfish (mostly in adults)