A milk protein allergy in infants is a serious problem. Both babies and mothers are affected. If your baby has a milk protein allergy, it’s important to determine which feeding option will help them thrive.

A milk protein allergy most often happens in babies who are fed cow’s milk formula. This occurs when the body’s immune system perceives cow’s milk protein as harmful and causes an allergic response.

According to a 2016 study published in the British Journal of General Practice, up to 7 percent of babies who are formula-fed are allergic to cow’s milk protein.

In some cases, though, it can occur in breastfed babies. According to the same 2016 study, up to 1 percent of babies who are breastfed develop an allergy to cow’s milk.

Certain genes have been identified in milk protein allergy. Up to 8 out of 10 children will outgrow the allergy by age 16 years, according to the American College of Allergy, Asthma, and Immunology.

Symptoms of a milk protein allergy often take place within minutes to a few days of exposure to cow’s milk. Infants may be exposed through formula or the breast milk of mothers who ingest cow’s milk or products made from cow’s milk.

Allergy symptoms may be gradual or occur rapidly.

Symptoms with a gradual onset may include:

  • loose stools, which may be bloody
  • vomiting
  • gagging
  • refusing to eat
  • irritability or colic
  • skin rashes

Symptoms with a rapid onset may include:

  • wheezing
  • vomiting
  • swelling
  • hives
  • irritability
  • bloody diarrhea
  • anaphylaxis

No single test exists to diagnose a milk protein allergy. Diagnosis occurs after reviewing symptoms and going through a process of elimination to rule out other medical conditions. Tests may include:

  • stool test
  • blood tests
  • allergy tests, including skin prick or patch tests
  • food challenge

Your healthcare provider may recommend an elimination diet.

They may have you feed your baby formula that’s free from cow’s milk or ask you avoid cow’s milk if you’re breastfeeding.

Proteins from the foods a breastfeeding mother eats can appear in breast milk within 3 to 6 hours and can remain for up to 2 weeks. Typically, an elimination diet will last for at least 1 to 2 weeks. Cow’s milk is then reintroduced to see if allergy symptoms return.

When it comes to feeding your baby, breastfeeding is best.

Breast milk is nutritionally balanced, offers protection against illnesses and infections, and reduces the risk for Sudden Infant Death Syndrome (SIDS). Babies who are breastfed are less likely to develop food allergies and even chronic diseases later in life.

The American Academy of Pediatrics recommends breastfeeding exclusively for at least the first 6 months of a child’s life, with breastfeeding to continue, whenever possible, for at least the first year of life.

The World Health Organization (WHO) also recommends breastfeeding exclusively for the first 6 months of life, with breastfeeding to continue until the child is at least 2 years old.

If you’re breastfeeding and your child develops a cow’s milk allergy, you’ll need to make dietary changes.

Eliminate dairy products, including:

  • milk
  • cheese
  • yogurt
  • cream
  • butter
  • cottage cheese

Milk protein is often hidden. It may be found in:

  • flavorings
  • chocolate
  • lunch meat
  • hot dogs
  • sausages
  • margarine
  • processed and packaged foods

Manufacturers are required to list major potential allergens, including milk, on food product labels. Read labels carefully to determine if products you eat contain milk.

Not every woman is able to breastfeed.

If your baby has a milk protein allergy and you’re unable to breastfeed, there are formula options that don’t contain cow’s milk.

  • Soy formula is made from soy protein. Unfortunately, between 8 to 14 percent of babies with milk allergy will also react to soy, according to the Asthma and Allergy Foundation of America. Extensively hydrolyzed formulas break cow’s milk protein down into small particles to make an allergic reaction less likely.
  • Babies who are unable to tolerate hydrolyzed formula may do well on an amino acid-based formula. This formula type is made of amino acids or protein in its simplest form.

Keep in mind that the more a formula is hydrolyzed, the less tasty it may be for some babies.

If your baby has symptoms of an allergy to milk protein, it may be hard to determine if the cause is a simple upset stomach or an allergy.

Don’t try to diagnose the issue or change formulas yourself. Consult your healthcare provider to get a proper diagnosis and to discuss treatment options.

Help your healthcare provider make the proper diagnosis with these tips:

  • Keep a record of your baby’s eating habits and symptoms.
  • If you breastfeed, keep a record of the foods you eat and how they affect your baby.
  • Learn about your family medical history, especially any food allergies.

As a mother, it’s painful to see your child in distress, especially from something as natural as eating. Don’t hesitate to reach out to friends or family members. You can also find a support group to help you develop coping strategies.

Knowing others are going through a similar situation is often enough to empower you to stay positive. Take comfort in the fact that many milk allergies can be controlled through dietary changes if you breastfeed or switch formulas.