Food Allergies

What is a food allergy? Suspect that your child may have a food allergy if she has allergic symptoms after eating certain foods. The most common reactions are hives, swelling of the mouth or diarrhea. Children with other allergic conditions, such as eczema, asthma, or hay fever have a higher rate of food allergies than non-allergic children.

Which foods cause allergic reactions? Overall, the most allergic food is the peanut. Five foods account for over 80% of food reactions: peanuts (and peanut butter), eggs, cow's milk products, soybeans (and soy formula), and wheat. If we add fish, shellfish, and tree nuts to the preceding 5 foods, these 8 foods account for over 95% of food reactions. Four foods (chocolate, strawberries, corn, and tomatoes) are commonly mentioned, but rarely cause any allergic symptoms. How can you be certain a food is causing your child's symptoms?

• First: Be a good detective. Keep a symptom diary for 2 weeks. Anytime your child has symptoms, write down the foods eaten during the preceding meal. After 2 weeks, examine the diary for foods that were repeatedly consumed on days your child had symptoms.
• Second: Eliminate the suspected food from the diet for 2 weeks. Record any symptoms that occur during this time. If you’ve eliminated the correct food, all symptoms should disappear. Most children improve within 2 days and almost all by 1 week.
• Third: Once you find the allergic food, avoid it. This should keep your child free of symptoms. If you’re breast-feeding, eliminate the food your child is allergic to from your diet. Food allergens can be absorbed from your diet and enter into your breast milk.
• Finally: If you eliminate a food from your child's diet, consult your healthcare provider. He may want to re-challenge your child with the suspected food to prove it definitely causes your child's symptoms. This step is never carried out if your child has experienced a severe or anaphylactic reaction to the food. Your healthcare provider will also determine if your child needs any vitamin or mineral supplements. Eliminating a single food does not cause any side effects. Eliminating a major food group (such as milk products) however, can cause vitamin D and calcium deficiency unless your child receives appropriate supplements.

If you have other questions about food allergies, consult your healthcare provider.

Disclaimer: This information is not intended to be a substitute for professional medical advice. It is provided for educational purposes only. You assume full responsibility for how you choose to use this information.

Author and Senior Reviewer: Barton D. Schmitt, M.D. FAAP

Last Review: 6/1/2008

Last Revised: 6/1/2000