Atopy patch test for early diagnosis of cow's milk allergy in preterm infants

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.

Malabsorption Syndromes and Food Intolerance

Feeding intolerance is ubiquitous in neonatal intensive care units with as many signs and symptoms as possible diagnoses. Optimizing nutrition is paramount in both preterm and term infants. Determining the cause of feeding intolerance and adjusting nutrition interventions is an important part of the daily care of newborns. This review discusses the role of malabsorption and food intolerance as possible causes of nutrition difficulties in the newborn.

Cows' Milk Allergy-Associated Constipation: When to Look for It? A Narrative Review

Constipation is a very common disorder, mostly functional in nature, that may persist for years in up to 35-52% of children. Food allergy prevalence, severity and persistence are increasing over time, and cows' milk protein is the commonest food allergen recognised to affect gastrointestinal motility in children. There is mounting evidence of the role of cows' milk (CM) allergy (CMA) in children with constipation. With this narrative review, we aim to provide clinicians with an updated and critical overview of food allergy-associated constipation. We searched Embase, Medline and the Cochrane Library, using keywords related to the topic. Only reviews and studies including children aged 0-17 years that were published in English were considered. Constipation has been reported in 4.6% of infants with CMA; the prevalence of food allergy underlying chronic constipation in children resistant to conventional treatment and presenting to tertiary clinics ranges between 28% and 78%. The identification of predisposing risk factors and of a specific phenotype of food allergy-induced constipation remains elusive. No allergic tests, radiological or motility investigations achieve sufficient sensitivity and specificity to screen children for CMA-related constipation. A 4-week cows' milk protein (CMP) elimination diet may be considered for children with chronic constipation resistant to conventional treatment and who lack alarm sign/symptoms of organic diseases. In subjects with ameliorated symptoms on CMP elimination, the diagnosis of CMA should be confirmed by a food challenge to avoid an unnecessary protracted diet.

Early Onset Allergic Proctitis in a Preterm Neonate-A Case Report and Review of the Literature

Cow's milk protein allergy/intolerance (CMPA/CMPI) is a common entity in the pediatric population with a nonspecific presentation ranging from gastrointestinal symptoms to systemic manifestations. Most infants with CMPI are term, and symptoms often appear in the week following the introduction of cow's milk-based formula. There is typically a significant delay in the onset of milk allergy in premature infants compared to full term. We report a rare case of a premature neonate who presented with symptoms of CMPA within the first 2 days of life.

How to feed a baby recovering from necrotising enterocolitis when maternal milk is not available

Necrotising enterocolitis (NEC) is a devastating disease with significant mortality and serious adverse outcomes in at least 50% including short gut and poor neurodevelopment. Research and management are complicated by a lack of robust clinical markers, and without histological confirmation, there is a risk of both underdiagnosis and overdiagnosis. Interunit variations in the thresholds for surgical referral, laparotomy and postmortem rates mean the actual incidence is difficult to determine, especially because the histological term 'NEC' is used in practice to describe a heterogeneous clinical syndrome. In this article, we discuss issues relating to choice of milk feed type following a clinical diagnosis of 'NEC' where mother's own milk is not available. We review common clinical concerns relating to feeding following NEC and the rationale for modifications of the macronutrient composition and quality of formula milk.

Use of extensively hydrolysed formula for refeeding neonates postnecrotising enterocolitis: a nationwide survey-based, cross-sectional study

OBJECTIVE

To evaluate the prevalence of and reasons for using extensively hydrolysed formulas (EHFs) of cow's milk proteins in the French neonatal units as well as the modality of their prescription for refeeding infants recovering from necrotising enterocolitis (NEC).

METHODS

A multicentre nationwide cross-sectional study using a questionnaire to address the prevalence of use and the reasons for prescribing EHF in hospitalised neonates and to examine the protocols and the actual reasons for their use for refeeding infants in recovery from NEC. The questionnaire was sent to only 1 senior neonatologist in each neonatal unit included in the study.

RESULTS

More than half of the French neonatal units participated in the survey. 91% of the surveyed units used EHF. Of 1969 infants hospitalised on the day the survey was run, 12% were fed on an EHF. 11% of the EHF prescriptions were due to previous NEC. The main reasons for using an EHF to feed infants post-NEC were the absence of human milk (75%) and surgical management of NEC (17%). When given, EHF was mainly prescribed for a period varying between 15 days and 3 months. None of the involved units continued using the EHF after 6 months of age. More than half of the surveyed units acknowledged hospitalising infants for the initiation of weaning EHF but only 21% of them tested these infants for cow's milk allergy.

CONCLUSIONS

The prevalence of EHF use in the French neonatal units is high. Refeeding infants post-NEC is one of the main reasons for such a high prevalence. The main incentive for using an EHF is the absence of human breast milk, either maternal or donor.

Manifestations of Cow's-Milk Protein Intolerance in Preterm Infants

OBJECTIVES

Cow's-milk protein intolerance (CMPI) is poorly recognized in preterm infants. This study examined the clinical events that preceded the diagnosis of CMPI in preterm infants.

METHODS

This was a retrospective study of infants in a level-III neonatal intensive care unit of those who received parenteral nutrition (PN) support during a 12-month period. Parameters assessed included birth weight (g), diagnosis, duration and frequency on PN, type of enteral feeds at initiation, and achievement of enteral autonomy. CMPI was diagnosed based on persistent feeding intolerance that resolved after change of feeds from intact protein to a protein hydrolysate or crystalline amino acid formula.

RESULTS

Three hundred forty-eight infants with birth weight (median/range) 1618 g (425-5110) received PN. Fifty-one (14%) infants required multiple courses of PN, and 19 of 348 (5%) were diagnosed with CMPI. The requirement for multiple courses on PN versus single course was associated with a high likelihood of CMPI: 14 of 51 versus 5 of 297, P < 0.001. Nine of the 14 infants identified with CMPI were initially diagnosed with necrotizing enterocolitis (NEC) after a median duration of 22 days (19-57) on intact protein feeds. After recovery from NEC, they had persistent feeding intolerance including recurrence of "NEC-like illness" (N = 3) that resolved after change of feeds to a protein hydrolysate or crystalline amino acid formula.

CONCLUSIONS

The requirement for multiple courses of PN because of persistent feeding intolerance after recovery from NEC and recurrence of "NEC-like illness" may be a manifestation of CMPI in preterm infants.

Diagnostic accuracy of atopy patch tests for food allergy in children with atopic dermatitis aged less than two years

BACKGROUND

Atopy patch tests (APT) have been introduced as a valuable tool for the diagnosis of food allergy. However, interpretation of the readout of APT requires further clarification.

OBJECTIVE

To investigate the accuracy of APT in identifying atopic sensitisation to hen's eggs (HE), cow's milk (CM), soybean and wheat in Chinese children with atopic dermatitis (AD) aged less than two years and to evaluate skin signs of APT for accurate diagnosis of food allergy.

METHODS

APT was performed and food allergy confirmed by open oral food challenges with HE, CM, soybean and wheat in 150 Chinese AD children aged less than two years. The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, positive (LR+) and negative likelihood ratio (LR-) of APT were calculated.

RESULTS

Erythema and infiltration were not sufficiently indicative of a positive APT. The PPV increased with the appearance of indurations and the number of papules. The true positive APT rate increased from scores of + to +++. The PPV and specificity were 100% while APT scores of +++ were obtained with HE, CM and wheat. The sensitivity of APT with HE, CM, soybean and wheat allergy ranged from 59.6% to 90.5%, while the specificity ranged from 82.1% to 92.4%.

CONCLUSION

The APT is a suitable method for the diagnosis of AD in Chinese children aged less than two years with food allergies. Erythema and infiltration are not sufficient indicators of APT positivity. The PPV increases with indurations and the number of papules.

Cow's milk allergy: from allergens to new forms of diagnosis, therapy and prevention

The first adverse reactions to cow's milk were already described 2,000 years ago. However, it was only 50 years ago that several groups started with the analysis of cow's milk allergens. Meanwhile the spectrum of allergy eliciting proteins within cow's milk is identified and several cow's milk allergens have been characterized regarding their biochemical properties, fold and IgE binding epitopes. The diagnosis of cow's milk allergy is diverse ranging from fast and cheap in vitro assays to elaborate in vivo assays. Considerable effort was spent to improve the diagnosis from an extract-based into a component resolved concept. There is still no suitable therapy available against cow's milk allergy except avoidance. Therefore research needs to focus on the development of suitable and safe immunotherapies that do not elicit severe side effect.

Milk allergy in the neonatal intensive care unit: comparison between premature and full-term neonates

BACKGROUND

There have been several reports on neonates with milk allergy in a neonatal ward. This type of allergy is mostly categorized as a non-IgE-mediated food allergy. Although most cases of milk allergy occur in the first few months of life, the differences in clinical characteristics between premature and full-term neonates are still unclear.

OBJECTIVE

This study aimed to clarify the differences in clinical characteristics of milk allergy between premature and full-term neonates.

METHODS

We retrospectively evaluated 2,116 neonates admitted to the Department of Neonatology, Chiba Kaihin Municipal Hospital, between 2001 and 2007.

RESULTS

We identified 24 neonates strongly suspected of having milk allergy because of symptoms, such as bloody stools, repeated vomiting, diminished sucking and abdominal distension, as well as objective laboratory findings of eosinophilia in stool cytology and/or positive results for a rectal milk challenge test. Twelve of these 24 neonates were premature (median gestational age, 31 ± 3 weeks; median birth weight, 1,656 ± 592 g) and the other 12 were full-term (median gestational age, 38 ± 1 weeks; median birth weight, 2,760 ± 560 g). There were no differences in symptoms and time to start of feeding between premature and full-term neonates, but there was a significant difference in the median postnatal age at onset (premature neonates: 23 days; vs. full-term neonates: 3.5 days; p < 0.01).

CONCLUSION

All premature neonates developed a milk allergy after 32 weeks of corrected gestational age, suggesting that the development of milk allergy requires a certain degree of immunological maturation.

Evolution of in vitro cow's milk protein-specific inflammatory and regulatory cytokine responses in preterm infants with necrotising enterocolitis

BACKGROUND

We have previously reported evidence of in vitro sensitisation to cow's milk protein in peripheral blood mononuclear cells (PBMCs) in preterm infants with necrotising enterocolitis (NEC). In the present study, we document the changes in the PBMC responses to stimulation with mitogen (phytohaemagglutinin) and cow's milk proteins β-lactoglobulin (β-lg) and casein over time: from the acute presentation of NEC, to initial recovery (reinitiation of enteral feeds), to full recovery (full feeding).

METHODS

Of the 14 preterm infants recruited with acute NEC, 12 were followed until fully enterally fed (2 died during the acute phase). Cytokine secretion (interferon-γ [IFN-γ], interleukin 4, [IL-4], IL-10, and transforming growth factor-β1 [TGF-β1]) by PBMCs in response to stimulation by phytohaemagglutinin, β-lg, and casein was measured by enzyme-linked immunospot in the acute phase and subsequently at recovery and full recovery.

RESULTS

The high levels of cytokine secretion (IFN-γ, IL-4, IL-10, and TGF-β1) observed in response to β-lg and casein in the acute phase increased by a further 50% to 100% at recovery (P < 0.005). At full recovery (full feeding), however, IFN-γ, IL-4, and IL-10 secretion response had returned to, or below, acute-phase levels, whereas the augmented TGF-β1 response was maintained (P = 0.005 vs acute level). This response pattern was similar for casein, and did not appear to be influenced by the nature of the feed used following NEC (breast milk/formula/hydrolysed formula).

CONCLUSIONS

The evolution of the cytokine response profile in parallel with the clinical recovery from NEC is consistent with a putative role for TGF-β1 in regulation of inflammation, and possibly also oral tolerance.

Diagnostic approach and management of cow's-milk protein allergy in infants and children: ESPGHAN GI Committee practical guidelines

OBJECTIVES

This guideline provides recommendations for the diagnosis and management of suspected cow's-milk protein allergy (CMPA) in Europe. It presents a practical approach with a diagnostic algorithm and is based on recently published evidence-based guidelines on CMPA.

DIAGNOSIS

If CMPA is suspected by history and examination, then strict allergen avoidance is initiated. In certain circumstances (eg, a clear history of immediate symptoms, a life-threatening reaction with a positive test for CMP-specific IgE), the diagnosis can be made without a milk challenge. In all other circumstances, a controlled oral food challenge (open or blind) under medical supervision is required to confirm or exclude the diagnosis of CMPA.

TREATMENT

In breast-fed infants, the mother should start a strict CMP-free diet. Non-breast-fed infants with confirmed CMPA should receive an extensively hydrolyzed protein-based formula with proven efficacy in appropriate clinical trials; amino acids-based formulae are reserved for certain situations. Soy protein formula, if tolerated, is an option beyond 6 months of age. Nutritional counseling and regular monitoring of growth are mandatory in all age groups requiring CMP exclusion. REEVALUATION: Patients should be reevaluated every 6 to 12 months to assess whether they have developed tolerance to CMP. This is achieved in >75% by 3 years of age and >90% by 6 years of age. Inappropriate or overly long dietary eliminations should be avoided. Such restrictions may impair the quality of life of both child and family, induce improper growth, and incur unnecessary health care costs.

The optimal diagnostic workup for children with suspected food allergy

Food allergy is defined as an abnormal immunologic reaction to food proteins that causes an adverse clinical reaction. In addition to well-known acute allergic reactions and anaphylaxis triggered by immunoglobulin E antibody-mediated immune responses to food proteins, there is an increasing recognition of cell-mediated disorders such as eosinophilic esophagitis and food protein-induced enterocolitis syndrome. More than 90% of food allergies in childhood are caused by eight foods: cow's milk, hen's egg, soy, peanuts, tree nuts, wheat, fish, and shellfish. The diagnostic workup for a child with suspected food allergy includes a detailed medical history, physical examination, food allergy screening tests, and responses to an elimination diet and an oral food challenge. None of the screening tests, alone or in combination, can definitely diagnose or exclude a food allergy. Novel diagnostic methods including those that focus on immune responses to specific food proteins or epitopes of specific proteins are under active study. Unconventional diagnostic methods are increasingly used, but they lack scientific rationale, standardization, and reproducibility. In selected cases, such as eosinophilic esophageal gastroenteropathies or food protein-induced gastroesophageal reflux disease, invasive procedures are mandatory for an accurate diagnosis. Properly done, an oral food challenge is still the gold standard in the diagnostic workup. An incorrect diagnosis is likely to result in unnecessary dietary restrictions, which, if prolonged, may adversely affect the child's nutritional status and growth.