Guidelines may encourage overdiagnosis of cow’s milk allergy in infants

According to a study published in Clinical and experimental allergy.

“We examined the frequency of symptoms associated in the guidelines with non-IgE-mediated cow’s milk allergy in children,” author Rosie Vincent, MBChB, a clinical researcher in dermatology at Bristol Royal Infirmary, told Healio.

“The study was prompted by the increase in diagnoses of non-IgE-mediated cow’s milk allergy despite an actual prevalence of around 1% and the increase in prescriptions for specialized infant formula in infants,” said Vincent, who is also an Honorary Clinical Fellow at the University of Bristol.

The researchers performed a secondary analysis of the data from the Tolerance Interrogation Study (EAT), who examined whether the early introduction of allergenic foods into an infant’s diet reduced the risk of developing an allergy to that food.

The 1,303 healthy infants in the cohort were exclusively breastfed until at least 3 months of age. The researchers randomly assigned them to a standard introductory group (SIG) or an early introductory group (EIG).

Infants in the EIG group were introduced to six allergenic foods, including cow’s milk in addition to breastfeeding. Infants in the SIG group were exclusively breastfed until about 6 months of age.

The researchers saw the infants during clinic visits when they were 3 and 12 months old. In addition, parents responded to monthly questionnaires about their baby’s general health and consumption of allergenic foods until their baby was 12 months old.

Questionnaires asked parents if their infant had had any adverse reactions to food since the 3-month assessment or since the previous questionnaire, such as eczema, breathing problems, or gastrointestinal problems.

International Milk Allergy Guidelines in Primary Care (iMAP) identifies colic, reflux, food refusal or aversion, diarrhea, constipation, pruritus, rash, and atopic dermatitis among their mild symptoms to moderate allergy to non-IgE-mediated cow’s milk. Symptoms of severe allergy include diarrhea, vomiting, abdominal pain, blood or mucus in the stool, and severe atopic dermatitis.

“The main finding of the study is the frequency of symptoms mentioned in the iMAP guidelines for non-IgE-mediated cow’s milk allergy,” said Vincent.

Specifically, 25% of families reported two or more mild to moderate non-IgE cow’s milk allergy symptoms each month from 3 and 12 months, and 1.4% reported severe symptoms. The researchers noted that these numbers peak at 3 months of age (mild to moderate, 38%; severe, 4.2%), when infants are not yet consuming cow’s milk.

By 12 months of age, 73.6% of infants had presented multiple mild to moderate symptoms, with 9.3% multiple severe symptoms, at least 1 month old.

The average monthly reporting of milk-related symptoms was 2.2% between 3 and 12 months, with the average for individual symptoms ranging from 0.2% for blood in stool to 45.8% for vomiting, with a peak at 3 months of age in 78.1% of infants.

Colic, vomiting, and abdominal discomfort were more common by 3 months of age and decreased with age, while food inversion and aversion increased in the first 12 months. Diarrhea and constipation also increased during infancy, while skin symptoms were more stable.

Fewer participants reached the threshold for severe symptoms of cow’s milk allergy, with abdominal pain reaching the highest percentage at 13.1% at 3 months. The most severe symptoms had a monthly reported prevalence of between 1% and 2%.

However, only 0.6% of EAT participants (n = 7 of 1,166) were eventually diagnosed with IgE-mediated cow’s milk allergy by age 3, of which 0.7% (n = 4 out of 597) from the SIG group and 0.5% (n = 3 out of 569) from the GIE group.

“These results suggest that the vast majority of children with these symptoms are not allergic to cow’s milk,” said Vincent.

At 6 months, the researchers found no difference in the proportion of children with two or more mild to moderate symptoms between those consuming and not consuming cow’s milk (29.5% versus 35.3%) or between those with or without eczema at the start (15.8% against 16.7%). This lack of difference persisted when the researchers examined infants with two or more severe symptoms (consumption vs. no consumption of cow’s milk, 2.2% vs. 1.1%; eczema, 1.1% vs. 1.3%).

The researchers caution that solid data should support guidelines for preventing the damage from overdiagnosis that exceeds the damage from missed and delayed cow’s milk allergy diagnoses they aim to prevent.

“Doctors should use this evidence as a benchmark. The frequency of these symptoms is in a representative group of normal, healthy infants. Physicians should also interpret these guidelines with caution to avoid medicalizing the infant’s normal symptoms, which in turn leads to unwarranted prescriptions for specialized infant formulas, at a cost to families … and negative outcomes for infant rates. ‘breastfeeding,’ said Vincent.

Additionally, the researchers said that mild, transient, or isolated symptoms should not be overinterpreted and diagnosis should be considered when symptoms are multiple, significant, persistent, and resistant to treatment. Parents, the researchers continued, should be encouraged to appreciate the normality of common infant symptoms.

“It is important not to sow the seeds of a suspected cow’s milk allergy unless there are sufficient grounds to do so. Doctors should be careful not to use the guidelines for non-IgE-mediated cow’s milk allergy without considering that the infant might just experience normal symptoms in the infant, ”said Vincent.

Research in this area should continue, Vincent added.

“In the absence of a simple diagnostic test for non-IgE cow’s milk allergy, more research is needed to identify which combination of symptoms is both specific and susceptible to the disease,” he said. she declared.

For more information:

Rosie Vincent, MBChB, can be reached at [email protected] or on Twitter @RosieVince.