Early-Life Respiratory Infections in Infants with Cow's Milk Allergy: An Expert Opinion on the Available Evidence and Recommendations for Future Research

An ESPGHAN Position Paper on the Diagnosis, Management, and Prevention of Cow's Milk Allergy

A previous guideline on cow's milk allergy (CMA) developed by the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) was published in 2012. This position paper provides an update on the diagnosis, treatment, and prevention of CMA with focus on gastrointestinal manifestations. All systematic reviews and meta-analyses regarding prevalence, pathophysiology, symptoms, and diagnosis of CMA published after the previous ESPGHAN document were considered. Medline was searched from inception until May 2022 for topics that were not covered in the previous document. After reaching consensus on the manuscript, statements were formulated and voted on each of them with a score between 0 and 9. A score of ≥6 was arbitrarily considered as agreement. Available evidence on the role of dietary practice in the prevention, diagnosis, and management of CMA was updated and recommendations formulated. CMA in exclusively breastfed infants exists, but is uncommon and suffers from over-diagnosis. CMA is also over-diagnosed in formula and mixed fed infants. Changes in stool characteristics, feeding aversion, or occasional spots of blood in stool are common and in general should not be considered as diagnostic of CMA, irrespective of preceding consumption of cow's milk. Over-diagnosis of CMA occurs much more frequently than under-diagnosis; both have potentially harmful consequences. Therefore, the necessity of a challenge test after a short diagnostic elimination diet of 2-4 weeks is recommended as the cornerstone of the diagnosis. This position paper contains sections on nutrition, growth, cost, and quality of life.

The Remaining Challenge to Diagnose and Manage Cow's Milk Allergy: An Opinion Paper to Daily Clinical Practice

Guidelines and recommendations for the diagnosis and management of cow's milk allergy (CMA) in childhood are based on scientific review of the available evidence. While this approach is the most rigorous, guidelines may not fully address all scenarios encountered by clinicians. Many symptoms of CMA overlap with other common childhood illnesses and are subjectively reported by the caregivers of the infant, as is the interpretation of the dietary interventions. Additionally, many healthcare professionals and caregivers do not follow the recommendations to perform an oral food challenge or reintroduction of cow's milk after a diagnostic elimination diet because (1) the infant is doing well and (2) the carer's fear of symptoms relapsing with this procedure. As a result, CMA in infants may be either under-diagnosed leading to reduced quality of life for families or over-diagnosed, resulting in unnecessary long-term elimination diets and increasing the risk for nutritional deficiencies. This paper discusses some of these controversial topics, focusing on misdiagnosis and mismanagement in clinical practice. The lack of objective diagnostic criteria can hamper the diagnosis and management of CMA in daily practice.

Evaluation of Cow's Milk Related Symptom Score [CoMiSS] accuracy in cow's milk allergy diagnosis

BACKGROUND

Cow's Milk-related Symptom Score (CoMiSS) is an awareness tool to recognize cow's milk allergy (CMA) symptoms in infants. We aimed to assess the best cut-off point of CoMiSS in our country and investigate other parameters suggested to raise the strength of CoMiSS in CMA diagnosis.

METHODS

We enrolled 100 infants with CMA-suggestive symptoms with documentation of CoMiSS initially and 4 weeks after cow milk-free diet (CMFD) followed by an open food challenge (OFC) test. Infants with symptom recurrence upon challenge were diagnosed with confirmed CMA.

RESULTS

Initial mean CoMiSS was 15.76 ± 5.29, being higher in the confirmed CMA group (84% of infants). Following CMFD, median CoMiSS significantly reduced to 1.5 in the confirmed CMA group compared to 6.5 in the negative group. Receiver operation characteristic (ROC) curve identified a CoMiSS score of ≥12 as the best cut-off value with 76.19% sensitivity, 62.50% specificity and overall accuracy of 74.00%. Mucoid stool, bloody stool and faltering growth were reported in 80, 41 and 52% of confirmed CMA infants, respectively, with considerable improvement following CMFD.

CONCLUSIONS

Our study revealed a CoMiSS score of ≥12 to be the best cut-off point. However, CoMiSS cannot be used alone for accurate diagnosis of CMA.

IMPACT

CoMiSS ≥12 can predict a positive response to CMFD; nevertheless, CoMiSS is a good awareness tool and cannot be regarded as a stand-alone CMA diagnostic test. CoMiSS reduction following CMFD was predictive of a reaction to OFC to diagnose CMA as well as for monitoring symptom improvement. Symptoms commonly associated with CMA as mucoid stool, bloody stool, marked abdominal distention not responding to medical treatment and faltering growth, in addition to their improvements in response to CMA are suggested parameters to be added to CoMiSS to improve its accuracy.

Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) Guidelines update - III - Cow's milk allergens and mechanisms triggering immune activation

Background

The immunopathogenesis of cow's milk protein allergy (CMPA) is based on different mechanisms related to immune recognition of protein epitopes, which are affected by industrial processing.

Purpose

The purpose of this WAO DRACMA paper is to: (i) give a comprehensive overview of milk protein allergens, (ii) to review their immunogenicity and allergenicity in the context of industrial processing, and (iii) to review the milk-related immune mechanisms triggering IgE-mediated immediate type hypersensitivity reactions, mixed reactions and non-IgE mediated hypersensitivities.

Results

The main cow’s milk allergens – α-lactalbumin, β-lactoglobulin, serum albumin, caseins, bovine serum albumins, and others – may determine allergic reactions through a range of mechanisms. All marketed milk and milk products have undergone industrial processing that involves heating, filtration, and defatting. Milk processing results in structural changes of immunomodulatory proteins, leads to a loss of lipophilic compounds in the matrix, and hence to a higher allergenicity of industrially processed milk products. Thereby, the tolerogenic capacity of raw farm milk, associated with the whey proteins α-lactalbumin and β-lactoglobulin and their lipophilic ligands, is lost.

Conclusion

The spectrum of immunopathogenic mechanisms underlying cow's milk allergy (CMA) is wide. Unprocessed, fresh cow's milk, like human breast milk, contains various tolerogenic factors that are impaired by industrial processing. Further studies focusing on the immunological consequences of milk processing are warranted to understand on a molecular basis to what extent processing procedures make single milk compounds into allergens.

The Cow's Milk Related Symptom Score: The 2022 Update

CoMiSS® was developed 7 years ago to increase the awareness of health care professionals towards the possibility that symptoms presented by infants could be related to cow’s milk. While CoMiSS was conceived mostly on theoretical concepts, data is now available from 25 clinical trials. Based on this extensive research using the tool since 2015, we aim to propose an updated CoMiSS. The evidence was reviewed, debated and discussed by 10 experts, of whom seven were part of the original group. The panel concluded that the cut-off previously proposed to indicate the likelihood that symptoms may be cow’s milk related should be lowered from ≥12 to ≥10. Data in healthy infants > 6 months are missing. Since the Brussels Infant and Toddlers Stool Scale (BITSS) was recently developed for non-toilet trained children, the Bristol Stool Scale was changed to the BITSS without changing the impact of stool characteristics on CoMiSS. Overall, CoMiSS raises awareness that symptoms might be cow’s milk related. New studies are needed to determine if the change in cut-off and other small adaptions improve its sensitivity and specificity. Data for CoMiSS is still needed in presumed healthy infants between 6 and 12 months old. There may also be regional differences in CoMiSS, in healthy infants as well as in those with cow’s milk allergy. Finally, we emphasize that CoMiSS is an awareness tool and not a diagnostic test.