Milk allergy hits the spotlight for long-term impacts, but is it diagnosed too often?

Two recent articles have looked at differing aspects of cow’s milk allergy, with both drawing attention to the importance of accurate diagnosis and careful long-term management of the condition, especially in young children.

Most studies indicate the true prevalence of cow’s milk allergy among children is around one per cent. The team behind a review of medical guidelines for diagnosis of cow’s milk allergy have suggested official guidelines may be resulting in up to 14 per cent of families believing their child has the condition.

Having analysed nine official guidelines for cow’s milk allergy published between 2012 and 2019, the reviewers found that many of the guidelines named common complaints in infants such as excessive crying, regurgitating milk and loose stools as indications of cow’s milk allergy.

Misdiagnosing milk allergy could lead to families or – through prescription subsidies – the government, unnecessarily paying for expensive specialist formula. The authors raised concerns that three of the nine guidelines they analysed were directly supported by formula manufacturers or marketing consultants, and over 80 per cent of all guideline authors reported a conflict of interest with formula manufacturers.

In another study, researchers looked at the long-term impacts of persistent cow’s milk allergies on the growth patterns of children. They found children with unresolved cow’s milk allergy had lower body weight and height compared with other children, including those with peanut and tree nut allergies.

The researchers did not seek to explain how cow’s milk allergy might be related to the growth deficiencies. However, they were able to show that among children included in the study, growth deficiencies became more pronounced as the children grew older.

These findings, coupled with the knowledge that children with cow’s milk typically restrict other common food allergens such as eggs, peanuts, and tree nuts from their diet, highlight how overdiagnosis of cow’s milk allergy could have long-term detrimental impacts on child health.

Reference 1: Munbilt et al. 2020 JAMA Pediatrics. Vol. 174(6) Pp. 599-608. DOI:10.1001/jamapediatrics.2020.0153

Reference 2: Robbins et al. 2020 Journal of Allergy and Clinical Immunology. Vol. 145(2) Pp. 713-716.e4. DOI:10.1016/j.jaci.2019.10.028