Cow’s milk protein allergy is the first food allergy in infants, but it is much less common than reported. Around 10% of families report it, whereas fewer than 1% of infants have a diagnosis confirmed by an oral food challenge. This discrepancy is the central point of the subject.
What do the figures say about cow’s milk protein allergy?
The ESPGHAN position paper, from the European Society for Paediatric Gastroenterology, Hepatology and Nutrition, published in 2023 in the Journal of Pediatric Gastroenterology and Nutrition, establishes the numerical framework.
- Approximately 10% of infants are reported by those around them to be allergic to cow’s milk proteins.
- Fewer than 1% actually are, after confirmation by an oral food challenge.
- The European EuroPrevall study found an overall incidence of 0.54%, with a confidence interval of 0.41 to 0.70%.
- Among exclusively breastfed infants, prevalence ranges from 0.5 to 0.7%.
In France, Assurance Maladie states that food allergy affects approximately 6% of children, across all foods. Cow’s milk proteins are among the allergens most often involved, along with eggs, peanuts and tree nuts.
Why is the gap between perception and diagnosis so large?
Because the signs are not specific. Regurgitation, crying, loose stools and redness occur in many infants without an allergy. ESPGHAN puts it unequivocally: with the exception of anaphylaxis, there is no symptom specific to allergy.
The distribution of reported manifestations is as follows: skin-related in 70 to 75% of cases, digestive in 13 to 34%, and respiratory in 1 to 8%. Anaphylaxis occurs in 1 to 4% of cases.
Two different mechanisms, two different time frames
The most useful distinction for parents concerns the time between milk consumption and the appearance of symptoms.
- IgE-mediated form. Symptoms generally occur within minutes of ingestion.
- Non-IgE-mediated form. Symptoms are delayed, occurring more than two hours later, most often between six and seventy-two hours afterward.
This second form is the most difficult to identify, precisely because the timing link is not apparent. It accounts for some consultations for unexplained crying, a subject we cover in our article on infant crying.
How is the diagnosis made?
Through an elimination diet followed by a reintroduction challenge, not by a simple blood test. ESPGHAN describes this sequence as the cornerstone of diagnosis.
- Elimination. One to two weeks for IgE-mediated forms, and two to four weeks for delayed forms.
- Oral food challenge. It starts with a very small dose, around one millilitre, then increases in stages to at least one hundred millilitres.
- Confirmation. After a negative challenge, milk is resumed daily at home, at least 200 ml per day for two weeks.
One point deserves emphasis: ESPGHAN does not recommend the atopy patch test for the routine diagnosis of non-IgE-mediated forms, because there is insufficient evidence.
What is not cow’s milk protein allergy
Lactose intolerance is an enzymatic digestive disorder with no immunological mechanism. It is rare in infants. Physiological regurgitation, which is very common, is not in itself a sign of allergy either.
What treatment is recommended, and which milks should be used?
Treatment is based on eliminating cow’s milk proteins under medical supervision, using a suitable substitute formula.
- First choice: an extensively hydrolysed cow’s milk protein formula tested in randomized clinical trials.
- Amino acid-based formula: reserved for severe forms or cases of marked undernutrition.
- Rice hydrolysate: a possible alternative, but less extensively studied.
- Soy formula: not a first choice; it may be considered for economic, cultural or taste-related reasons.
Goat’s and sheep’s milk are not fallback options. Assurance Maladie points out that their proteins have more than 85% similarity to those in cow’s milk. Commercial plant-based drinks are not infant formulas either and do not meet nutritional needs.
Breast milk itself does not cause an allergy. If an allergy is confirmed in a breastfed child, the mother’s diet is adapted; breastfeeding is never stopped as a matter of principle. Our official data on breastfeeding in France places this point in context.
Does the allergy disappear with age?
In a large majority of cases, yes. ESPGHAN reports that among children reassessed one year after diagnosis, 69% tolerated cow’s milk. The rate was 57% for IgE-mediated forms and 100% for non-IgE-mediated forms in the series concerned.
Reintroduction should be planned with a doctor and never attempted alone at home. It forms part of the broader schedule for introducing solid foods, for which we detail the official guidance in our article on food diversification according to ANSES.
Nutritional considerations
Prolonged elimination without a suitable substitute can lead to deficiencies, particularly in calcium, vitamin D and iron. Monitoring the growth curve is therefore inseparable from the diet. Our article on iron deficiency in infants details this particular risk.
Preparing bottles also follows specific rules, regardless of which milk is used. We review them in our articles on water for preparing bottles and microplastics and baby bottles.
Milk allergy and eczema: a frequent, but not systematic, link
Skin manifestations dominate the clinical picture, which explains the common confusion with atopic dermatitis. The two can coexist, but infant eczema does not imply a food allergy in most cases. Our article on infant eczema in figures provides the key estimates.
Key points
Cow’s milk protein allergy is real, but it is overdiagnosed by families by a ratio of approximately ten to one. Diagnosis involves supervised elimination followed by reintroduction, not prolonged exclusion decided on one’s own. In most cases, tolerance develops during the first few years.
This article presents published data and does not replace a diagnosis or prescription. Any suspected allergy in an infant should be assessed by a general practitioner or paediatrician.
Sources
- Vandenplas Y. et al., “An ESPGHAN Position Paper on the Diagnosis, Management, and Prevention of Cow's Milk Allergy”, Journal of Pediatric Gastroenterology and Nutrition, 2024, vol. 78, no. 2, pp. 386-413 (published online in 2023).
- Assurance Maladie (ameli.fr), “Food allergy: definition and symptoms”, updated 27 June 2025.
