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Article Summary:
- If you’re not sure what your infant or newborn is allergic to, an allergy test may help.
- Three types of allergy tests are skin prick tests, skin patch tests and blood tests.
- Your child can receive an allergy test at any age.
- Cow’s milk protein allergy is one of the most common allergies in infants.
What Is Infant Allergy Testing?
Allergy testing is done to determine what substance or allergen a person is allergic to.1 Infant allergy testing is important because it can help you understand what foods your child must avoid.2 If your doctor performs an infant or newborn allergy test, they’ll likely use a skin prick test or a blood test.2 Don’t worry, both of these infant allergy tests are relatively painless—at the most, your little one may feel a slight pinch.1
What Is a Skin Prick Test?
You can take your little one to an allergist or pediatric allergist who will determine if a skin prick test is necessary.2 During a skin prick test, the doctor will put protein extract of the suspected food allergen on your child’s skin and then lightly scratch their skin.2 The goal is for the protein extract to make contact with their immune system.2 If a hive-like bump (wheal) appears, the allergist measures the size of it and it indicates that your infant or newborn may be allergic to the food.2
What Is a Blood Allergy Test?
Blood allergy tests are also known as food-specific IgE antibody blood tests.2 This test measures the level of the food-specific immunoglobulin E (IgE) antibody that your little one’s body might make in response to allergies.2,3 If the test reveals that the level of IgE antibody is higher than normal, it means your child’s immune system makes an IgE antibody to the specific food protein and that they may be allergic to the food.2 The results for this test aren’t immediate; you’ll have to wait for the test to be reviewed by an allergist first.2
What Is a Skin Patch Test?
During a skin patch test, a patch with an allergen is taped to your baby’s skin for 24 to 72 hours.4 Typically, these patches are placed on your baby’s back.5 While the skin patch is on your baby’s back, make sure you keep the area dry.5 Giving your child a bath can make the patches loosen or fall off.5 Once the patch has been on your little one’s back for 24 to 72 hours, the doctor will take off the patch and check your baby’s skin to see if there are any signs of an allergic reaction.5
How Accurate Are Infant Allergy Tests?
A diagnosis of a food allergy cannot be made using just the test results; the entire clinical picture including history, physical exam and test results are needed for an allergist to make a diagnosis. This is because some people make an IgE antibody to a food but don’t have an allergy to it (they can eat the food without any allergy symptoms). This is why it is not recommended to test IgE antibody for multiple foods if there are no symptoms as this can increase the risk of an incorrect diagnosis. Negative skin prick tests and IgE blood tests are fairly reliable. This is because a negative skin prick test or IgE antibody blood test to a food means the immune system is not making an IgE antibody to the food so it unlikely to have IgE antibody triggered food allergy.2
When Can My Child Undergo Allergy Testing?
Pediatric allergists can test newborns up to children who are up to 18 years of age.2 In other words, there is no age minimum for an allergy test, and you don’t have to wait to see what your child is allergic to.2
What Are the Most Common Infant Allergies?
If your little one has a food allergy, they’re not alone—around 7% of babies and children have a food allergy.3 The most common food allergies include:
- Cow’s milk protein6
- Egg3
- Peanut3
- Tree nuts, like almonds, cashews and walnuts3
- Soy3
- Seafood, including fish, shellfish and crustaceans3
- Wheat3
- Sesame3
It’s important to note that if you’re breastfeeding and consume dairy products, cow’s milk protein is passed to your baby.7 Many infant formulas contain cow’s milk protein, so check the label if you know your child is allergic.7
What Are the Signs of Cow’s Milk Protein Allergy?
Symptoms of a cow’s milk protein allergy (CMPA) include:6
- Hives
- Diarrhea
- Blood in stools
- Wheezing or difficulty breathing
- Colic or irritability
- Vomiting
- Facial swelling or a swollen tongue, mouth, or throat
If you suspect your infant or newborn has a cow’s milk protein allergy, contact your doctor.7 Your doctor will work with you to determine if your newborn has cow’s milk protein allergy and get to the bottom of what’s causing your newborn’s symptoms. CMPA can result in immediate (IgE) or delayed (non-IgE) symptoms. 7
Take control of common cow's milk protein allergy concerns* such as colic^, eczema, vomiting, diarrhea with Nutramigen® A+® with LGG®. Talk to your doctor if you suspect your baby has cow’s milk protein allergy.
* HCPs evaluated infants with suspected cow's milk protein allergy by the follow-up visit and reported improvement in infants with the following common symptoms observed in the current study: 90% improvement in diarrhea, 74% improvement in reflux/regurgitation, 86% improvement in vomiting, 95% improvement in bloody stools, and 86% improvement in rash/eczema.
^ 90% infants experienced relief within 48 hrs, due to cow's milk protein allergy.
- https://www.healthlinkbc.ca/tests-treatments-medications/medical-tests/allergy-tests
- https://www.healthlinkbc.ca/healthy-eating-physical-activity/age-and-stage/infants-children-and-youth/food-allergy-testing
- https://www.healthlinkbc.ca/healthy-eating-physical-activity/age-and-stage/infants-children-and-youth/reducing-risk-food
- https://myhealth.alberta.ca/Health/aftercareinformation/pages/conditions.aspx?hwid=ug5344
- Emmert V, Lendvai-Emmert D, Eklics K, Prémusz V, Tóth GP. Current Practice in Pediatric Cow’s Milk Protein Allergy–Immunological Features and Beyond. International Journal of Molecular Sciences. 2023; 24(5):5025
- https://www.healthlinkbc.ca/health-topics/cows-milk-protein-allergy-babies
- http://gikids.org/digestive-topics/cows-milk-protein-allergy/