[Specific changes in gut microbiota and short-chain fatty acid levels in infants with cow's milk protein allergy]. / ç‰›å¥¶è›‹ç™½è¿‡æ•å©´å„¿è‚ é“èŒç¾¤ç‰¹å¼‚æ€§å˜åŒ–åŠçŸ­é“¾è„‚è‚ªé ¸æ°´å¹³åˆ†æž.

OBJECTIVES: To explore the changes in gut microbiota and levels of short-chain fatty acids (SCFA) in infants with cow's milk protein allergy (CMPA), and to clarify their role in CMPA. METHODS: A total of 25 infants diagnosed with CMPA at Children's Hospital Affiliated to Zhengzhou University from August 2019 to August 2020 were enrolled as the CMPA group, and 25 healthy infants were selected as the control group. Fecal samples (200 mg) were collected from both groups and subjected to 16S rDNA high-throughput sequencing technology and liquid chromatography-mass spectrometry to analyze the changes in gut microbial composition and metabolites. Microbial diversity was analyzed in conjunction with metabolites. RESULTS: Compared to the control group, the CMPA group showed altered gut microbial structure and significantly increased α-diversity (P<0.001). The abundance of Firmicutes, Clostridiales and Bacteroidetes was significantly decreased, while the abundance of Sphingomonadaceae, Clostridiaceae_1 and Mycoplasmataceae was significantly increased in the CMPA group compared to the control group (P<0.001). Metabolomic analysis revealed reduced levels of acetic acid, butyric acid, and isovaleric acid in the CMPA group compared to the control group, and the levels of the metabolites were positively correlated with the abundance of SCFA-producing bacteria such as Faecalibacterium and Roseburia (P<0.05). CONCLUSIONS: CMPA infants have alterations in gut microbial structure, increased microbial diversity, and decreased levels of SCFA, which may contribute to increased intestinal inflammation.

Description of a Novel Pathogenic Variant in the ARPC1B and a Severe Allergy in Two Infants.

Actinrelated protein 2/3 complex subunit 1B (ARPC1B) deficiency is an inborn error of immunity (IEI) characterized by a combination of immunodeficiency and immune dysregulation and classified as an IEI with allergic manifestations. Here, we describe two patients with pathogenic variants in the ARPC1B gene. The first patient presented with eczema and bronchospasm at six months of age. The second patient presented with eczema and milk protein allergy at five months of age. The c.899_944 (p.Glu300Glyfs*7) pathogenic variant was previously described, whereas the c.863del (p.Pro288Leufs*9) variant was novel. ARPC1B deficiency should be considered because of the severe allergic manifestations at an early age.

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.

Gut microbiota and inflammatory mediators differentiate IgE mediated and non-IgE mediated cases of cow's milk protein at diagnosis.

OBJECTIVE: Analyze fecal and blood samples at point of diagnosis in IgE mediated cow's milk protein allergy (CMPA) and non-IgE mediated (NIM)-CMPA patients to look for potential new biomarkers. PATIENTS AND METHODS: Fourteen patients with IgE mediated CMPA and 13 with NIM-CMPA were recruited in three hospitals in the north of Spain, and were compared with 25 infants from a control group of the same age range. To characterize intestinal microbiota, 16S rDNA gene and internal transcribed spacer amplicons of bifidobacteria were sequenced with Illumina technology. Fatty acids were analyzed by gas chromatography, meanwhile intestinal inflammation markers were quantified by enzyme-linked immunosorbent assay and a multiplex system. Immunological analysis of blood was performed by flow cytometry. RESULTS: The fecal results obtained in the NIM-CMPA group stand out. Among them, a significant reduction in the abundance of Bifidobacteriaceae and Bifidobacterium sequences with respect to controls was observed. Bifidobacterial species were also different, highlighting the lower abundance of Bifidobacterium breve sequences. Fecal calprotectin levels were found to be significantly elevated in relation to IgE mediated patients. Also, a higher excretion of IL-10 and a lower excretion of IL-1ra and platelet derived growth factor-BB was found in NIM-CMPA patients. CONCLUSIONS: The differential fecal parameters found in NIM-CMPA patients could be useful in the diagnosis of NIM food allergy to CM proteins.

Mexican consensus on cow’s milk protein allergy

Background: The aim of this study is to present the current views of a diverse group of experts on the diagnosis and treatment of Cow’s Milk Protein Allergy (CMPA) in children under 2 years of age in Mexico. Material and methods: The study, led by a scientific committee of five experts in CMPA, was divided into six phases, including a modified Delphi process. A total of 20 panelists, all of whom were pediatric specialists, participated in administering a comprehensive 38-item questionnaire. The questionnaire was divided into two blocks: Diagnosis and Treatment (20 items each). Results: Consensus was reached on all the proposed items, with an agreement rate of over 70% for each of them. As a result, a diagnostic and treatment algorithm was developed that emphasized the reduction of unnecessary diagnostic studies and encouraged breastfeeding whenever possible. In cases where breast milk is not available, appropriate use of hypoallergenic formulas was recommended. In addition, recommendations on treatment duration and gradual reintroduction of cow’s milk protein were provided. Conclusions: The recommendations endorsed by 20 Mexican pediatricians through this study are applicable to everyday clinical practice, thereby enhancing the diagnosis and treatment of children under 2 years of age with CMPA. This, in turn, will foster improved health outcomes and optimize the utilization of healthcare resources (AU)

Cow's Milk: A Benefit for Human Health? Omics Tools and Precision Nutrition for Lactose Intolerance Management.

Cow's milk (CM) is a healthy food consumed worldwide by individuals of all ages. Unfortunately, "lactase-deficient" individuals cannot digest milk's main carbohydrate, lactose, depriving themselves of highly beneficial milk proteins like casein, lactoalbumin, and lactoglobulin due to lactose intolerance (LI), while other individuals develop allergies specifically against these proteins (CMPA). The management of these conditions differs, and an inappropriate diagnosis or treatment may have significant implications for the patients, especially if they are infants or very young children, resulting in unnecessary dietary restrictions or avoidable adverse reactions. Omics technologies play a pivotal role in elucidating the intricate interactions between nutrients and the human body, spanning from genetic factors to the microbiota profile and metabolites. This comprehensive approach enables the precise delineation and identification of distinct cohorts of individuals with specific dietary requirements, so that tailored nutrition strategies can be developed. This is what is called personalized nutrition or precision nutrition (PN), the area of nutrition that focuses on the effects of nutrients on the genome, proteome, and metabolome, promoting well-being and health, preventing diseases, reducing chronic disease incidence, and increasing life expectancy. Here, we report the opinion of the scientific community proposing to replace the "one size fits all" approach with tailor-made nutrition programs, designed by integrating nutrigenomic data together with clinical parameters and microbiota profiles, taking into account the individual lactose tolerance threshold and needs in terms of specific nutrients intake. This customized approach could help LI patients to improve their quality of life, overcoming depression or anxiety often resulting from the individual perception of this condition as different from a normal state.

Mexican consensus on cow's milk protein allergy.

BACKGROUND: The aim of this study is to present the current views of a diverse group of experts on the diagnosis and treatment of Cow's Milk Protein Allergy (CMPA) in children under 2 years of age in Mexico. MATERIAL AND METHODS: The study, led by a scientific committee of five experts in CMPA, was divided into six phases, including a modified Delphi process. A total of 20 panelists, all of whom were pediatric specialists, participated in administering a comprehensive 38-item questionnaire. The questionnaire was divided into two blocks: Diagnosis and Treatment (20 items each). RESULTS: Consensus was reached on all the proposed items, with an agreement rate of over 70% for each of them. As a result, a diagnostic and treatment algorithm was developed that emphasized the reduction of unnecessary diagnostic studies and encouraged breastfeeding whenever possible. In cases where breast milk is not available, appropriate use of hypoallergenic formulas was recommended. In addition, recommendations on treatment duration and gradual reintroduction of cow's milk protein were provided. CONCLUSIONS: The recommendations endorsed by 20 Mexican pediatricians through this study are applicable to everyday clinical practice, thereby enhancing the diagnosis and treatment of children under 2 years of age with CMPA. This, in turn, will foster improved health outcomes and optimize the utilization of healthcare resources.

Diagnostic intervention improved health-related quality of life among teenagers with food allergy.

OBJECTIVES: The aim was to examine if a diagnostic intervention set up to assess current food allergy to cow's milk, hen's egg, fish, or wheat among teenagers had an impact on generic and disease specific health-related quality of life (HRQL). The study compared HRQL scoring before and two years after the intervention, and in relation to age matched controls without reported food allergy. METHODS: The study was performed within the Obstructive Lung Disease in Northern Sweden (OLIN) studies where a cohort study on asthma and allergic diseases among 8-year-old schoolchildren was initiated in 2006. At age 12 years, the 125/2612 (5%) children who reported allergy to cow's milk, hen's egg, fish, or wheat were invited to a diagnostic intervention including clinical examination, blood tests and evaluation by a pediatric allergist. Of 94 participants, 79 completed generic and disease specific HRQL questionnaires. Additionally, a random sample of 200 (62% of invited) children without food allergy from the OLIN cohort answered the generic HRQL questionnaire. The respondents of the HRQL questionnaires were re-examined two years later and 57 teenagers with and 154 without reported allergy participated. RESULTS: There were no significant differences in generic HRQL scores between teenagers with and without reported food allergy at study entry, or after the intervention. Among those with reported food allergy, we found a significant improvement in disease specific HRQL after the intervention (mean values: 3.41 vs 2.80, p<0.001). Teenagers with only food allergy had better disease specific HRQL compared to those with one, two or three concomitant allergic diseases, both before and after the intervention. Children with only food allergy significantly improved their HRQL after the intervention, 1.84 vs. 2.87 (p<0.001) but this association was not seen in children with one other allergic disorder (3.16 vs. 3.65, p = 0.121) or those with two or more allergic disorders (3.72 vs. 3.90, p = 0.148). CONCLUSION: The diagnostic intervention showed a long-term improvement of disease specific HRQL but not generic HRQL.

Cow's Milk-related Symptom Score (CoMiSS) values in presumed healthy European infants aged 6-12 months: a cross-sectional study.

The Cow's Milk-related Symptom Score (CoMiSS) is an awareness tool for evaluating cow's milk-related symptoms. Previous studies have focused on providing CoMiSS values for healthy and symptomatic infants aged 0-6 months. However, there is a notable gap in the literature concerning CoMiSS values for infants older than 6 months. This cross-sectional study aimed to determine CoMiSS values in presumed healthy infants who have completed 6 months and are up to 12 months old, hereafter referred to as 6 to 12 months old. Physicians from six European countries prospectively determined CoMiSS values in infants attending well-child clinics. Exclusion criteria included preterm delivery, acute or chronic disease, and the consumption of a therapeutic formula, dietary supplements (except vitamins), or medication. The following information was collected: gestational age, gender, age, type of feed (breast milk or infant formula), and complementary feeding. Descriptive statistics were summarized with mean and standard deviation for normally distributed continuous variables, median and IQR for non-normally distributed variables, and differences in CoMiSS values were analyzed with appropriate tests. Data from 609 infants were obtained. The overall median (Q1-Q3) CoMiSS values were 3 (1-5). Significant differences were found across age groups (p < 0.001), but not across groups based on gender (p = 0.551) or feeding type (p = 0.880).   Conclusions: This study provided CoMiSS values in presumed healthy infants aged 6-12 months. Additional studies should be conducted to establish the use of CoMiSS to assess cow's milk-related symptoms in infants 6 months and older. What is Known: • The Cow's Milk-related Symptom Score (CoMiSS) is an awareness tool for evaluating symptoms related to cow's milk. • CoMiSS values for presumed healthy infants aged 0-6 months infants are already available. What is New: • CoMiSS values in European infants aged 6-12 months are provided. • These CoMiSS values differed across various age groups but not across groups based on gender or feeding type.

Outcomes and factors associated with tolerance in infants with non-IgE-mediated cow's milk allergy with gastrointestinal manifestations.

OBJECTIVES: To evaluate outcomes of oral food challenge (OFC) test to assess tolerance in infants with non-IgE-mediated cow's milk allergy (CMA) with gastrointestinal manifestations and explore clinical data predictive of these outcomes. METHODS: Single-center retrospective study including infants (age < 12 months) who were referred for CMA between 2000 and 2018 and underwent OFC on follow-up. A univariate logistic regression test was performed to evaluate variables associated with the outcomes of the follow-up OFC test. RESULTS: Eighty-two patients were included, 50% were male. Eighteen patients had a positive OFC test (22%). Most patients had presented with hematochezia (77%). The median age of symptom onset was 30 days. Two-thirds of the patients were on appropriate infant formula (extensively hydrolyzed or amino acid-based formula), exclusively or in association with breastfeeding. The median time on an elimination diet before the OFC test was 8 months (Q1 6 - Q3 11 months). All cases with positive follow-up OFC tests (n = 18) had been exposed to cow's milk-based formula before the first clinical manifestation of CMA. Five out of eight cases with Food Protein-Induced Enterocolitis Syndrome (FPIES) had positive OFC tests. Exposure to cow's milk-based formula before diagnosis, a history of other food allergies, hematochezia and diarrhea were predictors of a positive OFC test. CONCLUSIONS: In infants with non-IgE-mediated CMPA with gastrointestinal manifestations, the use of cow's milk-based formula, a history of other food allergies, and hematochezia and diarrhea upon initial presentation were associated factors for the later achievement of tolerance.

Home-Based Double-Blind, Placebo-Controlled Challenges for Diagnosis of Delayed Gluten/Milk Hypersensitivity in Children.

BACKGROUND: Delayed hypersensitivity to gluten and milk protein is frequently reported but may be difficult to diagnose. OBJECTIVE: We aimed to explore if a method of home-based double-blind placebo-controlled food challenges (H-FC) can identify and reduce unnecessary elimination diets in children. METHODS: We included 73 of 92 children aged 1 to 17 years referred to a tertiary allergy clinic from 2011 to 2021 due to self-reported, delayed symptoms to gluten or milk. The children were randomized to H-FC, receiving gluten/milk protein or placebo for 5 to 7 days in a double-blind crossover manner, separated by 3 washout weeks. Patients/parents recorded symptoms using standardized forms. Two crossover periods were used from 2011 to 2016 and 3 periods from 2017 to 2021. A positive challenge required significantly more symptoms during the active period versus the placebo period. After the challenge, reintroduction of milk/gluten was assessed by a follow-up interview. The primary outcome was the proportion of children with a positive challenge. RESULTS: The children, with a mean age of 11 years, had followed a strict gluten-free or milk-protein-free diet for a median duration of 24 months (range: 3-180 months). A positive challenge was observed in 18 of 73 children (25%), more often using 2 (35%) compared with 3 challenge periods (12%). At follow-up, 44 of 55 (80%) children with a negative challenge had successfully reintroduced milk/gluten. CONCLUSIONS: H-FC may be an effective method in avoiding unnecessary elimination diets in children. Only 25% of the challenges were positive, and 80% of the children with negative challenges succeeded in reintroducing the food. Three challenge periods may be necessary to reduce false-positive outcomes.

Alergia a la leche de vaca: ¿se pueden evitar las pruebas de provocación oral? Un análisis probabilístico basado en datos clínicos / Cow's milk allergy: Can oral food challenges be avoided? A probabilistic analysis based on clinical data

Introducción. La prueba de provocación oral (PPO) para el diagnóstico de alergia a las proteínas de la leche de la vaca (APLV) presenta riesgos y requiere de recursos. Nuestro objetivo fue evaluar condiciones y pruebas complementarias para identificar una alta probabilidad de APLV. Población y métodos. Análisis secundario sobre estudio de pacientes atendidos en una unidad de alergia entre 2015 y 2018. Se determinaron las probabilidades prepruebas asociadas a los síntomas y sus combinaciones, y las probabilidades pospruebas luego de realizadas pruebas cutáneas y determinación de inmunoglobulina E (IgE) sérica. Resultados. Se evaluó la información de 239 pacientes. Se observaron probabilidades mayores al 95 % en pacientes con angioedema y combinación de urticaria y vómitos. Usando puntos de corte propuestos por Calvani et al., la combinación de vómitos con rinitis, sin angioedema, también superó el 95 %. Conclusión. Se ofrece una metodología para identificar pacientes en los que puede diagnosticarse APLV sin realización de PPO.

Introduction. The oral food challenge (OFC) for the diagnosis of cow's milk protein allergy (CMPA) poses risks and requires resources. Our objective was to assess conditions and complementary tests used to identify a high probability of CMPA. Population and methods. Secondary analysis of a study of patients seen at a unit of allergy between 2015 and 2018. Pre-testing probabilities associated with symptoms and their combinations and post-testing probabilities after skin prick testing and serum immunoglobulin E (IgE) levels were determined. Results. The data from 239 patients were assessed. A probability greater than 95% was observed for angioedema and a combination of urticaria and vomiting. Based on the cut-off points proposed by Calvani et al., the combination of vomiting with rhinitis, without angioedema, also exceeded 95%. Conclusion. A methodology is provided to identify patients in whom CMPA may be diagnosed without an OFC.

Food-induced anaphylaxis during infancy is associated with later sleeping and eating disorders.

BACKGROUND: Accumulating evidence suggests that food-induced anaphylaxis (FIA) may induce different psychological disorders (PDs). In this study, we aimed to further evaluate the effect of FIA, specifically when occurring in early life, on subsequent PDs development. METHODS: We conducted a population-based, retrospective, matched-cohort study of pediatric patients (age ≤ 18 years) treated at the "Clalit" healthcare organization during the period 2001-2021. Children diagnosed with FIA were propensity score-matched with patients without any allergies (controls) of similar demographic parameters. Associations between FIA and different PDs were examined by multivariable regression models. RESULTS: The cohorts comprised 545 FIA patients and 4514 controls. Most patients were <3 years old [87.6% of controls (N = 3955) and 87.3% of the FIA cohort (N = 476)]. In this age group, the major food allergens were cow's milk (N = 258; 54.2%), eggs (N = 60; 12.6%), and peanuts (N = 20; 4.2%). The multivariable regression model identified an association between FIA and any PDs (p < .001), sleeping disorders (p < .001), and eating disorders (p = .050). Kaplan-Meier curves revealed that patients who experienced FIA before 3 years of age had an increased cumulative risk over the follow-up time of developing any PDs, sleeping disorders, and eating disorders. CONCLUSION: FIA during the first 3 years of life increases the risk of later developing eating and sleeping disorders, which can last into adulthood. Further attention should be focused on accurately diagnosing these children.

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.

What is Known About Cow's Milk Protein Allergy in Preterm Infants?

Background: Cow's milk protein allergy (CMPA) is well described in term infants, as opposed to preterm infants. In preterm infants, CMPA shares many gastrointestinal symptoms with necrotizing enterocolitis (NEC). Objectives: To evaluate the presentation of CMPA in preterm infants and to investigate the different diagnostic and therapeutic options. Materials and Methods: We searched for the relevant literature using the medical databases PubMed, Web of Science, and the Cochrane Library. We performed a post hoc analysis on the 25 case reports included in this study. Results: Literature was scarce and heterogeneous. The majority of preterm infants with CMPA were exposed to bovine-based milk proteins before the development of symptoms. The most common clinical manifestations were bloody stools, vomiting, and abdominal distension. Of the 25 cases, only 7 (28%) retained human milk in their diet after diagnosis. In the larger studies, no study has human milk as primary feeding choice after diagnosis. Conclusions: Preterm infants exposed to a type of cow's milk-based formula in their first days of life have a higher risk of developing CMPA. Most of the preterm infants are no longer fed with human milk after the diagnosis of CMPA is made, which is in contrast with current nutrition guidelines in preterm infants. We strongly advocate that human milk with mothers on a cow's milk-free diet is the first choice of feed after the diagnosis of CMPA. Prospective studies are necessary to obtain more information regarding clinical presentation, diagnostic tools, and therapeutic approaches.

[Natural history and risk factors of IgE-mediated cow's milk protein allergy in infants].

Objective: To investigate the natural history and risk factors for continued allergy in infants with IgE-mediated cow's milk protein allergy (CMPA). Methods: This was a prospective cohort study that included 72 infants under 24 months of age diagnosed with IgE-mediated CMPA in the allergy clinic of the Children's Hospital, Capital Institute of Pediatrics from October 2019 to November 2020. General information, clinical manifestations, serum total IgE, cow's milk specific IgE, and cow's milk protein component specific IgE were collected. Follow-ups were conducted at 24 and 36 months of age, and the patients were divided into the persistent allergy group and the tolerance group based on whether they developed cow's milk tolerance at 36 months of age. Mann-Whitney U test, chi-square test, and binary Logistic regression were used for intergroup comparison and multivariate analysis. Results: Among the 72 CMPA children, there were 42 boys and 30 girls, with an age of 10 (7, 15) months at enrollment. Cow's milk protein tolerance was observed in 32 cases (44%) and 46 cases (64%) at 24 and 36 months of age, respectively. There were 26 cases in the persistent allergy group and 46 cases in the tolerance group. The proportion of respiratory symptoms, history of wheezing, positive specific IgE for α-lactalbumin and the total IgE level in the persistent allergy group were higher than that in the tolerance group (7 cases (27%) vs. 0, 6 cases (23%) vs. 2 cases (4%), 67% (14/21) vs. 26% (10/39), 225 (151, 616) vs. 48 (21, 185) kU/L, χ2=10.82, 4.16, 9.57, Z=4.07, all P<0.05). Multivariate Logistic regression analysis showed that anaphylaxis (OR=21.14, 95%CI 2.55-175.14, P=0.005), a history of allergic rhinitis (OR=5.94, 95%CI 1.54-22.86, P=0.005), elevated milk specific IgE (OR=1.04, 95%CI 1.01-1.08, P=0.024), and positive casein specific IgE (OR=6.64, 95%CI 1.39-31.69, P=0.018) were risk factors for continuous CMPA. Conclusions: Most infants with IgE-mediated CMPA can achieve tolerance within 3 years. Anaphylaxis, a history of allergic rhinitis, elevated milk specific IgE levels, and casein sensitization are risk factors for continuous allergy.

Oral food challenge in children with contact urticaria in reaction to cow's milk.

OBJECTIVE: To evaluate the relationship between the occurrence of contact urticaria in reaction to cow's milk in infants and the diagnosis of cow's milk allergy (CMA) established by supervised oral food challenge. METHODS: In this cross-sectional study, we identified 184 children who had undergone 221 oral food challenge (OFC) at a CMA reference center between July 2015 and August 2019. Of these, 23 (12.5%) had a history of contact urticaria to cow's milk and underwent a total of 30 OFC. Baked cow's milk OFC were excluded, and 21 children were included in the study. All data from clinical history and allergy tests (serum-specific IgE dosages and skin prick test [SPT] with reconstituted cow's milk formula) were recorded on standardized forms. The challenge was conducted with reconstituted cow's milk formula in increasing volumes every 15-20 min. RESULTS: 24 OFC were performed; 13/24 (54.2%) for diagnostic purpose and 11/24 (45.8%) to evaluate cow's milk tolerance. Allergy tests were positive in 14 patients (87.5%). Positive oral challenge outcomes were identified in 7/24. One patient had a late flare of atopic dermatitis and five children presented with immediate urticaria (two generalized urticaria and three perioral urticaria). The median papule diameter was 6.5 mm in patients with a positive OFC and 3.75 mm in the negative group (P = 0.02). CONCLUSION: The occurrence of contact urticaria might be the only manifestation among infants sensitized to cow's milk with tolerance to oral ingestion. Reactions due to oral challenge were related to a larger wheal diameter on the SPT.