Milk, eggs, soy, wheat, tree nuts, peanuts, fish, and shellfish are among the most
common foods that cause allergies.
Food allergies can cause serious and even deadly reactions. So it's important to
know how to recognize an allergic reaction and to be
prepared if one happens.
What Are the Signs & Symptoms of a Food Allergy?
With a food allergy, the body reacts as though that particular food product is
harmful. As a result, the body's immune
system (which fights infection and disease) creates antibodies to fight the food
a drop in blood pressure, causing lightheadedness or loss of consciousness (passing
People often confuse food allergies with food
intolerance because of similar symptoms. The symptoms of food intolerance can
include burping, indigestion, gas, loose stools, headaches, nervousness, or a feeling
of being "flushed." But food intolerance:
doesn't involve the immune system
can happen because a person can't digest a substance, such as lactose
can be unpleasant but is rarely dangerous
What Are the Most Common Food Allergens?
A child could be allergic to any food, but these eight common allergens account
for 90% of all reactions in kids:
In general, most kids with food allergies outgrow them. Of those who are allergic
to milk, about 80% will eventually outgrow the allergy. About two-thirds with allergies
to eggs and about 80% with a wheat or soy allergy will outgrow those by the time they're
5 years old. Other food allergies may be harder to outgrow.
What Happens in a Food Allergy Reaction?
Food allergy reactions can vary from person to person. Sometimes the same person
can react differently at different times. So it's very important to quickly identify
and treat food allergy reactions.
be very mild and only involve one part of the body, like hives on the skin
be more severe and involve more than one part of the body
happen within a few minutes or up to 2 hours after contact with the food
Food allergy reactions can affect any of these four areas of the body:
skin: itchy red bumps (hives); eczema;
redness and swelling of the face or extremities; itching and swelling of the lips,
tongue, or mouth (skin reactions are the most common type of reaction)
gastrointestinal tract: belly pain, nausea, vomiting, or diarrhea
respiratory system: runny or stuffy nose, sneezing, coughing,
wheezing, shortness of breath
cardiovascular system: lightheadedness or fainting
Sometimes, an allergy can cause a severe reaction called anaphylaxis,
even if a previous reaction was mild. Anaphylaxis might start with some of the same
symptoms as a less severe reaction, but can quickly get worse. The person may have
trouble breathing or pass out. More than one part of the body might be involved. If
it isn't treated, anaphylaxis can be life-threatening.
How Is a Food Allergy Diagnosed?
If your child might have a food allergy, the doctor will ask about:
your child's symptoms
how often the reaction happens
the time it takes between eating a particular food and the start of symptoms
whether any family members have allergies or conditions like eczema and asthma
The doctor will look for any other conditions that could cause the symptoms. For
example, if your child seems to have diarrhea after drinking milk, the doctor may
check to see if lactose intolerance
could be the cause. Celiac
disease — a condition in which a person cannot tolerate the protein gluten — also
can cause similar symptoms.
The doctor might refer you to an
(allergy specialist doctor), who will ask more questions and do a physical
exam. The allergist probably will order tests to help make a diagnosis, such as:
a skin test. This test
involves placing liquid extracts of food allergens on your child's forearm or back,
pricking the skin, and waiting to see if reddish raised spots (called wheals) form
within 15 minutes. A positive test to a food only shows that your child might be sensitive
to that food.
to check the blood for IgE antibodies to specific foods
If the test results are unclear, the allergist may do a food challenge:
During this test, a person slowly gets increasing amounts of the potential food
allergen to eat while being watched for symptoms by the doctor. The test must be done
in an allergist's office or hospital with access to immediate medical care and medicines
because a life-threatening reaction could happen.
More often, though, food challenge tests are done to see if people have outgrown
How Are Food Allergies Treated?
If your child has a food allergy, the allergist will help you create a treatment
plan. Treatment usually means avoiding the allergen and all the foods that contain
You'll need to read food labels
so you can avoid the allergen. Makers of foods sold in the United States must state
whether foods contain any of the top eight most common allergens: milk, eggs, fish,
shellfish, tree nuts, peanuts, wheat, or soy.
There's no cure for food allergies. But medicines can treat both minor and severe
symptoms. Antihistamines might be used to treat symptoms such as hives, runny nose,
or belly pain from an allergic reaction.
If your child has any kind of serious food allergy, the doctor will want him or
her to carry an epinephrine auto-injector in case of an emergency.
An epinephrine auto-injector is a prescription medicine that comes in a small,
easy-to-carry container. It's easy to use. Your doctor will show you how. Kids who
are old enough can be taught how to give themselves the injection. If they carry the
epinephrine, it should be nearby, not left in a locker or in the nurse's office.
Wherever your child is, caregivers should always know where the epinephrine is,
have easy access to it, and know how to give the shot. Staff at your child's school
should know about the allergy and have an action plan in place. Your child's medicines
should be accessible at all times. Also consider having your child wear a medical
Signs and symptoms of anaphylaxis that would require epinephrine include:
throat feels tight
swelling in the mouth
any symptoms from two or more body systems (skin, heart, lungs, etc.), such as
hives and belly pain
any other combination of two or more symptoms that affect different parts of the
Every second counts in an allergic reaction. If your child starts
having serious allergic symptoms, give the epinephrine auto-injector right away. Also
give it right away if the symptoms involve two different parts of the body, like hives
with vomiting. Then call 911 and take your child to the emergency
room. Your child needs to be under medical supervision because even if the worst
seems to have passed, a second wave of serious symptoms can happen.
It's also a good idea to carry an over-the-counter (OTC) antihistamine for your
child, as this can help treat mild allergy symptoms. Use
after — not as a replacement for — the epinephrine shot during life-threatening