Milk Allergy Frequently Overdiagnosed

Many infants in some countries are misdiagnosed with allergy to cow, sheep, or goat milk, and they're prescribed specialized formulas they don't need, according to a consensus study.

"Milk allergy overdiagnosis is common in some regions and can potentially harm mothers and infants," the authors write in Clinical & Experimental Allergy. "These new consensus recommendations on the safe detection and management of milk allergy in children under 2 years aim to reduce harms associated with milk allergy overdiagnosis."

"This guidance, developed by experts without commercial ties to the formula industry, aims to reduce milk allergy overdiagnosis and [to] support…breastfeeding and less use of specialized formula, compared with current guidelines," they add.

Up to 1% of European infants 2 years of age and younger are considered allergic to cow's milk. Prescriptions for specialized formula for bottle-fed infants allergic to cow's milk in Australia, England, and Norway have grown to over 10 times the expected volumes.

Lead study author Hilary I. Allen, National Heart and Lung Institute, Imperial College London, United Kingdom, and her colleagues on several continents developed practical guidance for providers on safely detecting and managing milk allergy in infants.

Due to lack of high-certainty research evidence in this area, they used the Delphi consensus method.

The study involved two rounds of anonymous consensus-building surveys and one formal meeting in 2021.

The team identified experts from diverse geographic and cultural settings by searching medical databases for the term "milk hypersensitivity." They asked those experts to recommend colleagues. The researchers also contacted experts with ties to international professional organizations, such as the International Board of Lactation Consultant Examiners, as well as societies associated with the World Allergy Organization.

The 17 study participants included clinicians and researchers in general practice, health visiting, lactation support, midwifery, nutrition, and relevant areas of pediatrics from Africa, Asia, Australia, Europe, the Middle East, and North America. Experts with recent conflicts of interest with the breastmilk substitute (formula) industry were excluded from the study. Five authors of earlier milk allergy guidelines and seven parents contributed feedback.

In each survey round, participants used a nine-point scale to rank the importance of each proposed statement that addressed prevention of overdiagnosis or underdiagnosis, support of breastfeeding women, and the role of specialized formula products.

Based on the number of total points participants assigned, each statement was classified as "essential," "recommended," "no consensus," or "excluded" due to lack of relevance.

The experts agreed on 38 essential statements in several categories, including:

• Maternal dietary restriction is often not necessary to manage milk allergy

• In infants with chronic symptoms who are exclusively breastfed, milk allergy diagnosis should be considered only in specific, rare circumstances

• Milk allergy diagnosis does not usually need to be considered for stool changes, aversive feeding, or occasional spots of blood in stool, if not related in time with milk protein ingestion

The consensus recommendations provide more restrictive criteria than earlier guidelines for detecting milk allergy, fewer maternal dietary exclusions, and less use of specialized formula.

During an Infant Formula Shortage in the US, a Timely Study

Jodi A. Shroba, MSN, APRN, CPNP, coordinator for the Food Allergy Program, Children's Mercy Kansas City, Missouri, welcomed the study's engagement of specialists in various fields and avoidance of bias from formula companies.

Jodi A. Shroba

"Food allergies have received a lot of attention, especially through websites and social media," Shroba, who was not involved in the study, told Medscape Medical News in an email. "Unfortunately, a lot of that information is incorrect and can lead to misunderstanding and misdiagnosis.

"This article helps guide practitioners through identifying the concerning symptoms of milk allergy vs. normal infant symptoms," she said. "It can help providers discern when testing, elimination diets, and changes in formula are warranted.

"This guidance emphasizes the reproducibility and specificity of symptoms, which are key elements of a food allergy diagnosis," she explained. "By eliminating unnecessary milk allergy labeling, we can keep infants on appropriate diets for their age, such as breastfeeding or milk-based formulas. Proper diagnosis can also reduce unnecessary financial strain of specialty formulas, stress to the family regarding feedings, and a restrictive diet for the breastfeeding mother."

The study will be useful to a wide range of healthcare providers, Jennifer Anne Dantzer, MD, assistant professor of pediatrics, Johns Hopkins Medicine, Baltimore, Maryland, said in an email.

Dr Jennifer Anne Dantzer

"With the current formula shortage, there has perhaps never been a more important time to do this study and provide additional guidance on who does or does not need special formula," noted Dantzer, who also was not involved in the study. "A milk allergy diagnosis impacts the child and the family, so it is very important to avoid overdiagnosis and to support the breastfeeding mother."

"These findings should provide reassurance that dietary exclusions for the breastfeeding mother are not needed for most children with milk allergy," she said. "If a milk allergy is suspected, the child should be referred to an allergist."

The authors recommend further related research into the safety and effectiveness of using the guidance in practice.

One coauthor reports financial relationships with a biotech company. Allen and her remaining coauthors, as well as Shroba and Dantzer, report no relevant financial relationships. The study was funded through fellowships.

Clin Exp Allergy. Published online May 26, 2022. Full text, Supplementary material

For more news, follow Medscape on Facebook, Twitter, Instagram, YouTube, and LinkedIn.