Cows milk protein allergy, the real deal that is, affects 2-3% of infants worldwide. It is the most common food allergy in the first years.
Cows milk protein allergy can manifest itself in the skin, gut and respiratory system with symptoms like wheeze, congestion, eczema, hives, reflux, constipation, anaemia, vomiting, feed refusal and growth failure. It is over and under diagnosed!!
Diagnosis can be tricky. There are allergy tests - but these will only tell us about IgE mediated food allergies (the ones that involve the immune system). Children with IgE mediated food allergies usually have symptoms within 2 hours after eating the food. So if you have a negative allergy screen it doesn't mean you don't have a food allergy, it just means you don't have an IgE mediated food allergy.
With non IgE mediated food allergies, symptoms appear 2 - 72 hours after eating the food. These are the hardest to diagnose - because who can remember what they ate 3 days ago?!!!
Some companies offer food allergy or intolerance tests that measure ‘IgG antibodies’, but these are not a reliable way of diagnosing cow’s milk allergy or intolerance. Other tests such as hair analysis, kinesiology testing and vega testing have also been found to be unreliable.
The best way to diagnose most food allergies is with an elimination diet. These involve the removal of the suspected allergen for around 4 weeks followed by a food challenge.
Elimination diets should really be supervised by a registered dietitian to avoid the risk for nutritional deficiencies - because the body's nutrient stores can deplete quickly! For example, when you remove cows milk protein you remove a valuable source of calcium, protein, vitamin A, vitamin D, phosphorous and potassium.
A dietitian will also ensure that the elimination diet is done properly because cows milk protein can be difficult to remove in its entirety. Its not just the obvious dairy that you need to remove, cows milk protein is hidden is cereals, biscuits, crisps, processed meats, stock cubes, gravy powders, margarine....just about anything really!! Goats milk and lactose free products are not suitable for a cows milk protein free diet!!! But they are so often used as an alternative!! If the elimination diet is not done properly, it can render your efforts to diagnose and rule out an allergy useless.
When it comes to diagnosing a baby we would either remove cows milk protein from the mom's breastfeeding diet or we would change the formula. Which formula we choose depends entirely on your baby's sensitivity to cows milk protein and of course the severity of the reaction - our options include either an extensively hydrolyzed formula or an amino acid formula. Soy formula is often another "go to" but we have our concerns with soy formula.
The key with diagnosis of a cows milk protein allergy is the all important food challenge. Too often I see children going onto a milk free diet for whatever reason and never coming off. I often wonder how many of these children just had reflux or just had constipation or just had a respiratory infection - because babies have these symptoms for other reasons other than cows milk protein allergy!!