2-7% of babies and toddlers and 0.1-0.5% of adults are allergic to the protein in cow’s milk. The duration of the allergy to the cow’s milk protein varies, but most children will have outgrown this allergy by the age of two to three years. Although it is often stated that the number of children with cow’s milk protein allergy is increasing, there is no scientific evidence to support this.
Cow’s Milk Protein Allergy (CMPA) is defined as an undesirable reaction to the milk protein caused by an abnormal reaction in the body’s immune system. Allergy to cow’s milk protein is the most frequently diagnosed food allergy in infants and toddlers. Recovery often occurs naturally and most children grow out of their allergy. The duration of an allergy to cow’s milk protein varies, but most children outgrow the allergy before they reach the age of 2 or 3 years. Despite the lack of evidence that CMPA is becoming more prevalent, the percentage of parents believing their child has CMPA (or any other food allergy) ranges from 5% to 20%. Before any dietary advice is given, an adequate diagnosis must be made by a medical professional.
The diagnosis for cow’s milk protein allergy starts with an examination of the clinical symptoms associated with food allergy, such as dermatological problems, gastrointestinal complaints and/or respiratory problems. Also an abnormality in a child’s growth curve can be an indication of food allergy. After the physical examination, the child’s diet can be examined, in particular the milk intake. The next step is an elimination diet (at least four weeks), from which all food products containing cow’s milk are eliminated. A decline in complaints may indicate a cow’s milk protein allergy. However, if the complaints do not decline, cow’s milk can be re-introduced into the diet. This should also be done when there is an indication of cow’s milk protein allergy, as an increase in complaints after re-introduction of cow’s milk into the diet confirms the diagnosis for cow’s milk protein allergy. This method is called a provocation test. After the diagnosis, a general practitioner or dietitian can give appropriate dietary advice.