Food Allergy

Definition

• Allergic reaction to a food

Symptoms

• Widespread hives and facial swelling is the most common symptom. Hives are raised pink bumps with pale centers (welts). They look like mosquito bites.
• Mouth itching and swelling
• Runny nose and coughing
• Vomiting and diarrhea.
• Life-threatening allergic reactions must include trouble breathing and/or swallowing. The medical name is an anaphylactic reaction. Most have a sudden onset within 10 to 20 minutes. All start within 2 hours of food exposure. People with anaphylactic reactions carry an emergency kit like Epi-Pen.

Causes

• 8 foods cause 90% of food allergies
• In the first year of life: cow's milk, soy milk and egg
• Older children: peanuts, tree nuts, fish, shellfish and wheat
• Shellfish include shrimp, crab, lobster, clams, oysters and scallops
• Tree nuts include all the nuts (such as almonds and cashews) except peanuts.
• Of children with a proven food allergy, 40% have severe reactions. The other 60% do not.
• Peanuts and tree nuts are the most common triggers for severe allergic reactions.

Cross Reactions With Other Foods - Children with allergies below can react to other foods:

• Cow's milk allergy: 90% react with goat's milk and 40% with soy milk
• Egg: 5% with chicken
• Peanut: 5% with other legumes (like peas or beans). About 30% also react to tree nuts.
• Tree nut : 40% with other tree nuts
• Fish: 50% with other fish. Only 10% also react to shellfish.
• Shellfish: 70% with other shellfish
• Melon: 90% with banana and avocado

How Long do Food Allergies Last?

• Cow's milk: 80% outgrown by age 16
• Soy milk: 80% by age 16
• Egg: 70% by age 16
• Peanut: 20% by age 16
• Tree nut: 10% by age 16

Prevention of Allergic Disease by Diet:

• Most allergic diseases such as food allergies, eczema and asthma cannot be prevented.
• Helpful: Breastfeeding only for 6 months or longer
• Not helpful: Diet limits on certain foods for pregnant or breastfeeding women
• Not helpful: Soy formulas instead of cow's milk formula
• Not helpful: A delay in starting baby foods past 6 months
• Not helpful: A delay in starting high-risk foods. Examples are peanut butter or eggs.
• Source: AAP (2008)