Western children are being misdiagnosed with a milk allergy with just one per cent allergic to dairy – despite 14 per cent of parents claiming their child can’t tolerate it.
Researchers from Imperial College London found that medical guidelines for diagnosing babies with cow’s milk allergies don’t consider ‘normal infant behaviour’.
Guidelines currently say symptoms of cow’s milk allergy include excessive crying, regurgitating milk and loose stools – all common in normal, healthy babies.
Dr Robert Boyle, lead study author at Imperial College London, said misdiagnosing milk allergy could lead to other conditions with similar symptoms being missed.
The Imperial team also found that eight in ten guideline authors reported a conflict of interest – having a possible financial relationship with formula manufacturers.
Children are being misdiagnosed with a milk allergy with just one per cent of infants allergic to dairy – despite 14 per cent of parents claiming their child can’t tolerate it. Stock image
Researchers examined nine official guidelines for cow’s milk allergy published between 2000 and 2019 from a range of organisations primarily in Europe.
The team found that less than one per cent of infants had cow’s milk allergy in a recent European birth cohort study of 12,000 babies in nine countries.
The exact countries aren’t clear but it included the UK, Australia and Russia.
In addition to this, the analysis suggests the prescription of specialist formulas for babies with cow’s milk allergy had increased significantly between 2000 and 2018 without any evidence for an increase in cow’s milk allergy.
Milk allergy is most common in children under two and is categorised into two different types including IgE mediated and non-IgE mediated.
In IgE mediated, a reaction involves part of the immune system, called IgE. Symptoms include vomiting, hives and in very rare cases a severe reaction that causes difficulty breathing called anaphylaxis.
Symptoms of non-IgE mediated reactions may include vomiting, diarrhoea or excessive crying.
Researchers said the nature of these symptoms means they are often confused with normal symptoms in young babies.
Lead study author Dr Daniel Munblit, an associate professor at Sechenov University, said in the nine guidelines – seven suggested including milder symptoms as indication of non-IgE cow’s milk allergy.
‘Many of these symptoms are present normally in babies, and will get better with time,’ said Munblit.
‘Non-IgE cow’s milk allergy affects less than one per cent of infants whereas troublesome vomiting, crying or eczema each affect 15-20 per cent of babies.’
Misdiagnosing an allergy could lead to ‘breast-feeding mothers needlessly following restricted diets – or even stopping breast-feeding altogether,’ said Boyle.
‘It can also lead to families and the NHS unnecessarily paying for expensive specialist formula,’ he added.
Guidelines came from a range of medical organisations several countries predominantly in Europe.
Seven of the nine guidelines advised breast-feeding women to cut out all dairy from their diet if their child has a suspected cow’s milk allergy.
Studies suggest less than one millionth of the protein from cow’s milk travels through to breast milk, which would be too small to trigger a reaction in most allergic children, the team said.
Eight out of ten of all guideline authors had declared a conflict of interest with formula manufacturers and therefore could be profiting from the advice.

The team found that less than one per cent of infants had cow’s milk allergy in a recent European birth cohort study of 12,000 babies in nine countries including the UK, Australia and Russia. Stock image
Three guidelines were directly supported by formula manufacturers, with 81 per cent of all guideline authors reporting a conflict of interest.
Scientists said manufacturers could be undermining women’s confidence in breastfeeding to influence practitioners and parents to use specialised formula in place of a cheaper alternative.
‘Formula manufacturers may gain from promoting increased cow’s milk allergy diagnosis by influencing practitioners and parents to use a specialised formula in place of a cheaper formula,’ said Boyle.
He said they could also be ‘undermining women’s confidence in breastfeeding, so that specialised formula is used in place of breastmilk.
‘We must not only critically appraise our current guidelines, and dissociate the development of guidelines from those who may profit from them, but also ensure we are giving each family the best possible care by avoiding overdiagnosis of cow’s milk allergy.’
Dairy allergy was one of the earliest food allergies to be recorded – as early as ancient Greece – in a text attributed to the doctor Hippocrates.
Globally about 68 per cent of people have some degree of lactose intolerance, according to an earlier study published in the Lancet.
The authors found it varies dramatically around the world with parts of Asia and Africa seeing levels of up to 75 per cent compared to 28 per cent in parts of Europe.
This new study focused primarily on European countries, the 1 per cent intolerance figure in babies will be different in other parts of the world.
Findings were published in the JAMA Pediatrics journal.