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If you have read our other Cow’s Milk Allergy (CMA) articles, you may know that it is amongst one of the most common food allergies in infancy and early childhood. CMA is a hypersensitivity reaction to one or more proteins found in cow’s milk and dairy products. When a baby is allergic to cow’s milk, their immune system, which normally fights infections, overreacts to one or more proteins in the cow’s milk. As a result, every time the baby drinks cow’s milk or eats milk products, the body thinks these proteins are harmful which causes them to have a negative reaction.
We have compiled a few frequently asked questions when it comes to cow’s milk allergy.
Read on to find more about suspecting CMA, signs and symptoms, and the diagnosis of CMA.
CMA usually resolves by the age of one (4). If CMA is not outgrown by one year of age, it is recommended to schedule a visit with a registered dietitian to ensure the baby’s diet is nutritionally complete. Since most infants outgrow the allergy, elimination diet is only for a limited period and re-evaluation should be done periodically. Reintroduction begins after 6 months of avoidance, typically between the age of 9 to 12 months of age (2).
Most babies with CMA are otherwise healthy and growing well. A subset of babies with CMA may develop IgE allergies later in life, which is more common if babies have existing and/or family history of allergies, eczema, or asthma.
If you suspect your baby has CMA, go visit your family doctor or pediatrician to confirm the allergy. If possible, take a picture of the baby’s stool to show your doctor. If your baby is experiencing severe symptoms (lethargy, paleness, dehydration), then visit the emergency department for immediate care.
If the baby is being breast-fed, the mother should record what she ate in the last 48 hours. If the baby has not been diagnosed with CMA yet, this may help identify which foods are causing mucus or blood in the stool. Although blood and mucus can be a common symptom of CMA, It is important to speak to your doctor to rule out other causes of blood and mucus in the stools in infancy.
CMA will not impact your child’s ability to meet developmental milestones if the allergy is diagnosed and managed. Once the cow’s milk protein is removed and a baby is receiving good nutrition and hydration, then the baby should be able to thrive and grow as normal.
Typical symptoms include (3):
There is no blood test available to determine CMA. Your doctor will recommend an oral food challenge, where cow’s milk protein is removed for two weeks to determine if symptoms improve. If the symptoms resolve or improve, then cow’s milk is reintroduced to determine if the symptoms come back. If the symptoms reappear, CMA is confirmed.
Symptoms of CMA can present as early as one week of age, and symptoms can show immediately or months later. Immediate CMA is when symptoms appear almost immediately after consuming cow’s milk, whereas delayed CMA may take hours or days for symptoms to appear.
CMA and lactose intolerance are often confused but are not the same. Babies with CMA react to any form of cow’s milk and the reaction is to the PROTEIN, whereas babies with lactose intolerance can often tolerate some amount of cow’s milk and the reaction is to the SUGAR in milk (lactose). CMA involves the immune system, whereas lactose intolerance does not. Symptoms of lactose intolerance can be similar to symptoms of CMA as both involve the gut. It’s important to note that babies DON’T develop lactose intolerance (it cannot occur before approximately 3 years of age). If you are unsure if your child’s symptoms reflect those of CMA, visit your doctor. (3)
There is a range of symptoms with CMA, from mild to more severe. Anaphylaxis cannot occur with CMA as it is not an IgE mediated allergy. If your child is experiencing swelling of the throat, wheezing, dizziness, an increased heart rate, or an itchy, raised rash, anaphylaxis may be occurring, and it is important to get care from a hospital immediately. If a healthcare professional thinks a baby is experiencing or at risk of anaphylaxis, they may prescribe an adrenaline auto-injector pen to be administered.
Unless otherwise indicated, the information in this article is from our CDHF Talks with pediatric gastroenterologist, Dr. Lara Hart here.
Content reviewed by Amy Chow, RD
Amy Chow is a Registered Dietitian based in Langley, BC. Amy is your go to Registered Dietitian if you’re looking for support with gut health, food allergies, diabetes, eating disorders and pediatric nutrition. With a decade of experience, she is passionate about inspiring you to feel confident about nutrition and bringing joy back to eating. When she’s not working, Amy enjoys spending time outdoors with her family and in the kitchen trying out new recipes! www.chowdownnutrition.com