Food allergies are common, but not as common as some parents believe.
Food allergies do occur in up to 6 to 8% of children, but many more parents think that their children have reactions to foods that aren't really caused by allergic reactions, including:
- lactose intolerance
- hyperactivity (sugar or caffeine)
- food aversions (a child simply doesn't like to eat certain foods)
These can be caused by intolerances to food instead, or may just be a coincidence and have nothing to do with a specific food. Allergy testing can help to sort out whether or not your child really has food allergies or not.
Unlike food intolerances, true food allergies occur when a food triggers an immune system mediated reaction. This reaction involves the antibody IgE (immunoglobulin E), which causes certain immune system cells to release histamine, leading to most of the symptoms of a food allergy.
The foods that are most likely to cause food allergies, or allergy foods, include eggs, milk, peanuts, nuts, soy, wheat, fish and shellfish. You can be allergic to almost any food though, including many fruits and vegetables (oral allergy syndrome).
Of course, if your child has a reaction after eating certain foods, whether it is an allergy or intolerance, you should likely avoid that food. The big difference is that food allergies can be much more severe, so you want to be more careful about avoiding foods that your child might be truly allergic to. Also, you should learn to recognize food allergy symptoms so that you can be prepared to treat your child and get him help if he has a serious allergic reaction.
Symptoms of Food Allergies
Symptoms of food allergies usually begin fairly quickly after your child eats a specific food that triggers a reaction, and usually within a few minutes or hours.
You should suspect food allergies if your child develops one or more of the following symptoms after eating a specific food, including:
- difficulty breathing
- angioedema (a swollen tongue or swelling around a child's eyes and lips, etc.)
- itching in a child's mouth or throat
- abdominal pain
- low blood pressure (hypotension)
- loss of consciousness
Although congestion and sneezing can be symptoms of a food allergy, it is important to keep in mind that they are usually not the only symptoms that your child will have. Instead, your child will likely also have hives, wheezing, or angioedema, in addition to congestion.
Kliegman: Nelson Textbook of Pediatrics, 18th ed.
Adkinson: Middleton's Allergy: Principles and Practice, 6th ed.