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Milk Allergy in Infants
Almost all infants are fussy at times. But
sometimes infants are excessively fussy because they have an allergy to the
protein in cow's milk, which is the basis for most commercial baby
formulas.
A person of any age can have a
milk allergy, but it is more common among infants. Approximately 2% to
3% of infants have a milk allergy, and they typically outgrow it.
If you think that your child has a milk allergy,
talk with your child's doctor. There are tests that can diagnose
the condition and alternatives to milk-based formulas and dairy products that your doctor can recommend.
What Is a Milk
Allergy?
A milk allergy occurs when the child's
immune system mistakenly sees the milk protein as dangerous and tries to fight
it off. This starts an allergic reaction, which can cause an infant to be fussy
and irritable, and cause an upset stomach and other symptoms.
Most children who are allergic to cow's milk also react to goat's milk
and sheep's milk, and some of them are also allergic to the protein in soy
milk.
Infants who are breastfed have a lower risk of
developing a milk allergy than infants who are formula fed, but researchers
don't fully understand why some children develop a milk allergy and others
don't. It's believed that in many cases, the allergy is genetic.
Typically, a milk allergy goes away on its own
by the time a child is 3 to 5 years old, but some children never outgrow
it.
A milk allergy is not the same thing as
lactose intolerance, the inability to digest the sugar lactose,
which is rare in infants and more common among older kids and adults.
Symptoms of a Milk
Allergy
Symptoms of cow's milk protein allergy will generally
appear within the first few months of life. An infant can experience
symptoms either very quickly after feeding (rapid onset) or not until
7 to 10 days after consuming the cow's milk protein (slower onset).
The slower-onset reaction is more common. Symptoms
may include loose stools (possibly containing blood), vomiting, gagging,
refusing food, irritability or colic, and skin rashes. This type of
reaction is more difficult to diagnose because the same symptoms may occur with
other health conditions. Most children will outgrow this form of allergy by
2 years of age.
Rapid-onset
reactions come on suddenly with symptoms that can include irritability,
vomiting, wheezing, swelling, hives, other itchy bumps on the skin, and bloody
diarrhea. In rare cases, a potentially severe allergic reaction
called anaphylaxis can occur and affect the baby's skin,
stomach, breathing, and blood pressure. Anaphylaxis is more common in other food
allergies than in a milk allergy.
Diagnosing a Milk
Allergy
If you suspect that your infant is allergic to milk,
call your baby's doctor. The doctor will
likely ask about any family history of allergies or food intolerance and
then do a physical exam. There's no single lab test to accurately diagnose a
milk allergy, so your doctor might order several tests to make the diagnosis and
rule out any other health problems.
In addition to a stool test and a blood test, the
doctor may order an allergy skin test, in which a small amount of the milk
protein in inserted just under the surface of the child's skin with a needle. If
a red, raised spot called a wheal emerges, the child may
have a milk allergy.
The doctor may also request an oral challenge test.
After you stop feeding your baby milk for about a week, the doctor will have the
infant consume milk, then wait for a few hours to watch for any allergic
reaction. Sometimes doctors repeat this test to reconfirm the
diagnosis.
Treating a Milk
Allergy
If your infant has a milk allergy and you are
breastfeeding, it's important to restrict the amount of dairy products that you
ingest because the milk protein that's causing the allergic reaction can
cross into your breast milk. You may want to talk to a dietician about finding
alternative sources of calcium and other vital nutrients to replace what you
were getting from dairy products.
Since January 2006, all food makers must
clearly state on package labels whether the foods contain milk or
milk-based products, indicating this in or next to the ingredient list on the
packaging. Keep in mind, though, that this law applies only to foods packaged
after the start of 2006, so some foods packaged before then may not have any
information about food allergens.
If you are formula-feeding your infant,
your doctor may advise you to switch to a soy protein-based formula.
If your infant can't tolerate soy, the doctor may have you switch to
a hypoallergenic formula, one in which the proteins are broken
down into particles so that the formula is less likely to trigger an allergic
reaction.
Two major types of hypoallergenic formulas are
available:
- Extensively hydrolyzed formulas have cow's milk
proteins that are broken down into small particles so that they are less
allergenic than the whole proteins in regular formulas. Most infants who have
a milk allergy can tolerate these formulas, but in some cases, they still
provoke allergic reactions.
- Amino acid-based infant formulas, which contain
protein in its simplest form (amino acids are the building blocks of
proteins). This may be recommended if your baby's condition doesn't improve
even after a switch to a hydrolyzed formula.
There are also "partially hydrolyzed" formulas on
the market, but they are not considered truly hypoallergenic and they can still
provoke a significant allergic reaction.
The formulas available in the market today are
approved by the U.S. Food and Drug Administration (FDA) and created through a
very specialized process that cannot be duplicated at home. Goat's milk, rice
milk, or almond milks are not safe and are not
recommended for infants.
Once you switch your baby to another formula, the
symptoms of the allergy should go away in 2 to 4 weeks. Your child's doctor will
probably recommend that you continue with a hypoallergenic formula up until the
baby's first birthday, then gradually introducing cow's milk into his or
her diet.
If you have any questions
or concerns, talk with your child's doctor.
Reviewed by: Steven Dowshen,
MD