Food allergies occur when a child’s body reacts to a specific food as if it were a harmful substance. The immune system sends antibodies to fight off the food allergen. The antibodies release chemicals, such as histamine, which trigger symptoms, creating an allergic reaction. In the United States, approximately six million children and 6% of children under age three have a food allergy.
Common Food Allergies
A child could be allergic to many different foods, but 90% of all reactions in children occur from these eight common allergens:
- Tree Nuts (e.g., almonds, cashews, pecans, pistachios)
- Shellfish (e.g., shrimp, crab, crawfish)
Breastfed infants can experience an allergic reaction to a food ingested by the mother. Children who are allergic to milk, eggs, soy, and wheat often outgrow the allergy, while outgrowing a nut or seafood allergy is far less common.
Symptoms and Signs of Food Allergies
Symptoms can range from mild to severe. Mild symptoms include:
- Skin rash or hives
- Runny nose or congestion
- Tingling of the tongue, lips, or throat
- Coughing or sneezing
- Abdominal pain
- Upset stomach, nausea, or vomiting
More severe symptoms include:
- Swelling of the lips, tongue, or throat
- Difficulty swallowing
- Wheezing or shortness of breath (asthma)
- Drop in blood pressure, which may cause a child to feel faint, weak, or confused
- Chest pain
- Turning blue or loss of consciousness
A severe allergic reaction is called anaphylaxis and can be potentially life threatening. Typically during anaphylaxis, several areas of the body are affected, which can cause breathing difficulties and requires immediate medical attention.
Testing for Food Allergies
In order to confirm a food allergy, your doctor will most likely recommend additional testing which may include the following:
Skin prick test (SPT): A small amount of the food allergen is placed on the back or forearm. The doctor then gently pricks or scratches the skin surface to see if a reaction occurs. The test is usually done in the doctor’s office with results in about 30 minutes.
Blood test, which is also called radioallergosorbent test (RAST): This checks for the presence of immunoglobulin E (IgE) antibodies, which trigger allergy symptoms.
Food challenge: The child is fed the suspect food in small to increasingly larger doses in order to test for a reaction. The test is done in a controlled medical environment so the reaction can be immediately treated.
Food elimination diet: A short-term (usually 2–4 weeks) trial period in which the suspect food is eliminated and possibly gradually reintroduced while symptoms are monitored.
Treating Food Allergies
Unfortunately, there is not a cure for food allergies. Treatment usually involves avoiding the foods that contain the allergen causing the reaction. Milder symptoms can be treated with steroids, inhalers, and antihistamines. For more severe cases, you may need to keep epinephrine autoinjectors (EpiPens) at all locations where your child spends time. If you ever have to use an EpiPen on your child, you should take your child to the hospital immediately for observation and additional treatment.