Updated: Sep 10, 2021
I have been super curious about the cow milk protein allergy since SO many of my clients have babies with milk (and soy and gluten) allergies or intolerance. Studies show that up to 1 in 7 (15%) infants have a cow milk protein allergy – although it may be more like 1 in 20 based on more controlled studies.
Cow Milk Protein Allergy Basics
There is no doubt that moms and dads who have babies with cow milk protein allergy (CMPA) are super educated on this topic. When you have a baby who has a rash, cough, wheezing (scary!), diarrhea, reflux, is inconsolable, or refuses to eat – you are desperate to figure out why! But for those who haven’t dealt with this first hand, let me catch you up on some of the basics.
Formula Fed Babies
Formula fed babies have a higher risk (2-5%) of having a cow milk protein allergy (CMPA) than breastfed babies (0.4-2.1%). This is because there is much less cow milk protein (CMP) in breastmilk than there is in a CMP-based-formula - like 100,000x less! Less protein... less chance to react to it.
Most Common Protein Allergy
CMPA is the most common milk protein allergy. Compare it to soy protein – where just 0.25% of babies have a soy protein allergy (that is 1 in 400)!
CMPA + Soy
Babies who have CMPA are at a higher risk (10-30%) of having a soy protein allergy as well – this is why so many breastfeeding mamas have to eliminate both dairy and soy from their diets. The reason for this...? An antibody specific to CMP has an affinity to a component of soy-based formulas (glycinin).
Babies who have a CMPA are also allergic to goat, buffalo, and ewe milk – but can tolerate camel’s milk (although not sure camel’s milk is readily available?).
Babies with CMPA have an increased risk (13-20%) of also having a beef allergy.
*Note – The percentages above are not the amount of increased risk, but rather the percentage of babies who have the cited condition.
Cow Milk Protein Allergy Diagnosis
Figuring out if your baby has a cow milk protein allergy (CMPA) can be a process.
Most babies with CMPA develop symptoms in at least two organ systems –
skin (50–60%) and
respiratory tract (20–30%).
Because GI and skin symptoms are very nonspecific (they can occur for a variety of reasons) – determining their cause can be confusing and frustrating. See below to see a list of symptoms that could indicate your baby has CMPA.
Currently, an elimination diet is the gold standard for diagnosing CMPA. This means switching your baby’s formula from a CMP-based-formula to an alternative formula, or for a breastfeeding mom, eliminating all foods with CMP from her diet. If symptoms improve after elimination, then reintroduce restricted items to see if symptoms return. Check out the algorithm (from The College of Family Physicians of Canada) for details.
Formula fed babies may actually improve faster (within 72 hours) than breastfed babies (after 7 days) once CMP is removed from their diet. In both breastfed and formula fed babies, however, colitis (inflammation and irritation of the colon which causes blood in stools) can take up to 3 weeks to heal. Some symptoms in formula fed babies may take up to a week to resolve.
NOTE - In order to provide adequate calcium to your baby during the elimination diet, be sure to take calcium supplements (1000 mg per day divided into several doses) each day.
Is there hope for an actual “test” to assist with diagnosis of CMPA? Studies show that using both a skin prick test and a blood test (of IgE antibodies) can diagnose one type of cow milk protein allergy (IgE mediated – 54%). These tests are often completed by Allergists for babies who have severe allergies – those who could potentially have anaphylaxis if reintroduced to the CMP. However, researchers are currently working on ways to diagnose the other type of CMPA (non-IgE mediated – 46%) with a patch test. Basically – stay tuned. For now, you must eliminate and watch for change.