Shortly after Ben began eating his lunch, his childcare provider
noticed he seemed to be trying to scratch an itch in his mouth.
After he vomited and began wheezing, the care provider sought
medical treatment for Ben, who was later diagnosed with a food
allergy, in this case to peanuts.
Along with milk, eggs, soy, wheat, tree nuts, and shellfish,
peanuts are among the most common foods that cause
allergies
.
Learning how to recognize an allergic reaction will help you get
your child the medical care needed if a reaction occurs. If your
child has already been diagnosed with a food allergy, it's
important to know:
- how to accommodate your child's dietary needs
- what emergency preparations to make in case your child has an
allergic reaction
About Food Allergies
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 allergen, the substance in the food that triggers the
allergy.
The next time a person comes in contact with that food by
touching or eating it or inhaling its particles, the body releases
chemicals, including one called histamine, to "protect"
itself. These chemicals trigger allergic symptoms that can affect
the respiratory system, gastrointestinal tract, skin, or
cardiovascular system. These symptoms might include a runny nose,
an itchy skin rash, a tingling in the tongue, lips, or throat,
swelling, abdominal pain, or wheezing.
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 be caused by a person's inability to digest certain
substances, such as lactose
- can be unpleasant but is rarely dangerous
According to the U.S. Food and Drug Administration (FDA), up to
6% of children in the United States under age 3 have food
allergies. They are less common in adults but, overall, food
allergies affect nearly 11 million people in the United States.
Common Food Allergens
A child could be allergic to any food, but these eight common
allergens account for 90% of all reactions in kids:
-
milk
- eggs
-
peanuts
- soy
- wheat
- tree nuts (such as walnuts and cashews)
- fish
- shellfish (such as shrimp)
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 are harder to outgrow. Only about 20% of
people with allergies to peanuts and about 10% of those allergic to
tree nuts outgrow the allergies. Fish and shellfish allergies
usually develop later in life and are even more rarely
outgrown.
Food Allergy Reactions
Food allergy reactions can vary from person to person. Some can
be very mild and only involve one part of the body, like hives on
the skin. Others can be more severe and involve more than one part
of the body. Reactions can occur within a few minutes or up to a
few hours after contact with the food.
Food allergy reactions can affect any of the four following
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:
abdominal pain, nausea, vomiting, or diarrhea
- respiratory tract:
runny or stuffy nose, sneezing, coughing, wheezing, shortness of
breath
- cardiovascular system:
lightheadedness or fainting
A serious allergic reaction with widespread effects on the body
is known as anaphylaxis. This sudden, potentially life-threatening
allergic reaction involves two or more of the body areas listed
above. In addition, there also can be swelling of the airway,
serious difficulty with breathing, a drop in blood pressure, loss
of consciousness, and in some cases, even death.
Diagnosing a Food Allergy
If you suspect that your child might have a food allergy,
contact your doctor. To diagnose an allergy, the doctor will
likely ask about:
- your child's symptoms
- how often the reaction occurs
- the time it takes between eating a particular food and the
start of the first 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 rather than a food allergy.
Celiac disease
- a condition in which a person cannot tolerate gluten, a protein
found in wheat and certain other grains - also can mimic the
symptoms of food allergies.
If the doctor suspects a food allergy, you'll likely be
referred to an allergy specialist, who will ask more questions,
perform a physical exam, and probably perform tests to help make a
diagnosis.
One of those tests might be a skin test. The 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 certain food only shows that your child
might be allergic to that food - the allergist may do additional
tests for confirmation.
The allergy specialist might also perform blood tests, called
RASTs (radioallergosorbent tests), which check the blood for IgE
antibodies to specific foods. The results show the concentration of
IgE in the blood. For several foods, different cutoffs indicate a
high likelihood of an allergy. If someone has both a positive skin
test and and a RAST above the cutoff, an allergy to that food is
diagnosed and no further testing is needed.
If the test results are still unclear, the allergist may
perform a food challenge. (More often, though, this test is done to
determine if someone has outgrown a certain allergy.) During this
test, a person might be given gradually increasing amounts of
the potential food allergen to eat while being watched for symptoms
by the doctor. The test should only be performed in an
allergist's office or hospital that has access to immediate
medical care and medications because a life-threatening reaction
could occur.
Treating a Food Allergy
After diagnosing your child with a food allergy, the allergist
will help you create a treatment plan. No medication can cure food
allergies, so treatment usually means avoiding the allergen and all
the foods that contain it.
You'll need to familiarize yourself with
food labels
so you can avoid the allergen. Since 2006, a new food labeling law
has made this a little easier. Makers of packaged foods are
required to clearly state, in or near the ingredient lists, whether
the product contains milk, eggs, fish, shellfish, tree nuts,
peanuts, wheat, or soy.
Although there's no cure for food allergies, medications can
treat both minor and severe symptoms. Antihistamines might be used
to treat symptoms such as hives, runny nose, or abdominal pain
associated with an allergic reaction.
If your child wheezes or has
asthma
flares (also called attacks) as the result of a food allergy, the
doctor will likely recommend that a bronchodilator such as
albuterol (which can be inhaled from a handheld pump device) be
taken right away to reduce breathing difficulties.
But remember:
If your child experiences an allergy-triggered asthma attack,
it's important to consider also giving epinephrine and
seek emergency medical treatment immediately
, in case the asthma symptoms are part of anaphylaxis.
Epinephrine is often used to treat severe allergic reactions, or
anaphylaxis. If your child has severe food allergies, your
allergist will want you to have two epinephrine autoinjectors
(commonly called EpiPens) on hand at all times in case of a
life-threatening reaction. This will mean keeping epinephrine in
your home, briefcase or purse, and also at relatives' homes and
your child's day care or school.
Signs and symptoms of anaphylaxis that would require epinephrine
include:
- hoarseness
- sensation of tightness in the throat
- difficulty breathing
- any symptoms from two or more of the body systems, such as
hives and abdominal pain, or any other combination of two or more
symptoms that affect different parts of the body
After your child receives epinephrine, you should go immediately
to a hospital emergency room so additional treatment can be given,
if needed. Also, they'll observe your child for at least 4
hours to watch for signs of a second wave of symptoms (called a
biphasic reaction) that occurs in many cases.
You and your child's allergist should work together to
develop a written food allergy emergency action plan to give to the
school, childcare provider, and any other caregivers.
Reviewed by:
Hemant P. Sharma, MD
Date reviewed: November 2007
Originally reviewed by:
Stephen J. McGeady, MD
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
© 1995-2009 The Nemours Foundation/KidsHealth. All rights reserved.