Dietary Intervention during Weaning and Development of Food Allergy: What Is the State of the Art?

Food allergy (FA) affects approximately 6-8% of children worldwide causing a significant impact on the quality of life of children and their families. In past years, the possible role of weaning in the development of FA has been studied. According to recent studies, this is still controversial and influenced by several factors, such as the type of food, the age at food introduction and family history. In this narrative review, we aimed to collect the most recent evidence about weaning and its role in FA development, organizing the gathered data based on both the type of study and the food. As shown in most of the studies included in this review, early food introduction did not show a potential protective role against FA development, and we conclude that further evidence is needed from future clinical trials.

Molecular Mechanism and Clinical Effects of Probiotics in the Management of Cow's Milk Protein Allergy.

Cow's milk protein allergy (CMPA) is the most common food allergy (FA) in infancy, affecting approximately 2% of children under 4 years of age. According to recent studies, the increasing prevalence of FAs can be associated with changes in composition and function of gut microbiota or "dysbiosis". Gut microbiota regulation, mediated by probiotics, may modulate the systemic inflammatory and immune responses, influencing the development of allergies, with possible clinical benefits. This narrative review collects the actual evidence of probiotics' efficacy in the management of pediatric CMPA, with a specific focus on the molecular mechanisms of action. Most studies included in this review have shown a beneficial effect of probiotics in CMPA patients, especially in terms of achieving tolerance and improving symptoms.

COVID-19, anosmia, and ageusia in atopic children.

More than a year and a half after the beginning of the coronavirus disease 2019 (COVID-19) pandemic, symptoms, such as loss of smell and taste (anosmia and ageusia, respectively), remain difficult to characterize and quantify, especially in children, since no validated tests to assess these disorders are available. However, these symptoms can also be seen in children, although less frequently than observed in the adult population. In this article, we present the results of a national survey that collected the responses of 267 Italian pediatricians on the presence of anosmia and ageusia in children affected by COVID-19. These data were then compared with existing literature.

Allergic rhinitis, microbiota and passive smoke in children: A pilot study.

BACKGROUND: Allergic rhinitis (AR) is one of the most common allergic diseases affecting children. Objective assessment of nasal obstruction is possible through active anterior rhinomanometry (AAR). Several factors, such as passive smoke exposure (PSE), are triggers for worsening nasal obstruction and chronic inflammation. PSE affects bacterial eubiosis in the upper respiratory tract. This study evaluates the influence of PSE and cotinine levels on both nasal obstruction and local microbiome composition in children with AR. METHODS: Fifty patients (aged between 6 and 16 years) with AR monosensitized grass pollen were enrolled. They underwent skin prick tests, a nasal swab to evaluate the microbial composition of the anterior nostrils, a basal AAR, a post-decongestion AAR, and spirometry. Serum cotinine levels were assessed to evaluate PSE. RESULTS: A significantly lower percentage of mean nasal flow (mNF%) was observed before and after hydrazine administration in subjects exposed to passive smoke (Exp group) compared with the non-exposed group. In contrast, higher cotinine levels were observed in the Exp group than in the controls. PSE has been associated with a decrease in biodiversity and a change in the nasal microbiome composition; instead, although to a different extent, the abundance of specific taxa resulted in being correlated to cotinine levels and nasal flow. CONCLUSION: Children with AR exposed to passive smoke with positive serum cotinine could represent a risk factor for developing nasal obstruction and microbial dysbiosis, suggesting their possible role in pathophysiological processes.

Probiotics Function in Preventing Atopic Dermatitis in Children.

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by relapsing eczematous injuries and severe pruritus. In the last few years, the AD prevalence has been increasing, reaching 20% in children and 10% in adults in high-income countries. Recently, the potential role of probiotics in AD prevention has generated considerable interest. As many clinical studies show, the gut microbiota is able to modulate systemic inflammatory and immune responses influencing the development of sensitization and allergy. Probiotics are used increasingly against AD. However, the molecular mechanisms underlying the probiotics mediated anti-allergic effect remain unclear and there is controversy about their efficacy. In this narrative review, we examine the actual evidence on the effect of probiotic supplementation for AD prevention in the pediatric population, discussing also the potential biological mechanisms of action in this regard.

Selective IgA Deficiency and Allergy: A Fresh Look to an Old Story.

Selective IgA deficiency (SIgAD) is the most common human primary immune deficiency (PID). It is classified as a humoral PID characterized by isolated deficiency of IgA (less than 7 mg/dL but normal serum IgG and IgM) in subjects greater than 4 years of age. Intrinsic defects in the maturation of B cells and a perturbation of Th cells and/or cytokine signals have been hypothesized to contribute to SIgAD pathogenesis. The genetic basis of IgA deficiency remains to be clarified. Patients with SIgAD can be either asymptomatic or symptomatic with clinical manifestations including allergy, autoimmunity and recurrent infections mainly of the respiratory and gastrointestinal tract. Studies analyzing allergy on SIgAD patients showed prevalence up to 84%, supporting in most cases the relationship between sIgAD and allergic disease. However, the prevalence of allergic disorders may be influenced by various factors. Thus, the question of whether allergy is more common in SIgAD patients compared to healthy subjects remains to be defined. Different hypotheses support an increased susceptibility to allergy in subjects with SIgAD. Recurrent infections due to loss of secretory IgA might have a role in the pathogenesis of allergy, and vice versa. Perturbation of microbiota also plays a role. The aim of this review is to examine the association between SIgAD and atopic disease and to update readers on advances over time at this important interface between allergy and SIgAD.

Is oxidative stress involved in vernal keratoconjunctivitis? Results from a pilot study in children.

BACKGROUND: Vernal keratoconjunctivitis (VKC) is a rare chronic conjunctivitis characterized by a predominantly eosinophil-mediated inflammatory disorder that could develop critical complications such as blindness. Oxidative stress plays a pivotal role in the pathogenesis of several allergic diseases. The role of oxidative stress has been hypothesized in VKC, but no study explored this issue. Furthermore, cyclosporine A (CsA) exerts an anti-inflammatory and antioxidant action on the conjunctiva. This study aimed to assess the oxidative stress in VKC patients and controls and to study the effect of CsA on oxidative stress in these subjects. METHODS: Thirty-six consecutive children, including 12 VKC (nine males, 75%; mean age 10.17; SD ± 2.48) patients without treatment, 12 VKC patients treated with CsA (nine males, 75%; mean age 9.08; SD ± 2.75), and 12 controls (CT) (seven males, 58%; mean age 8.58; SD ± 1.78), were recruited. A cross-sectional study was performed to compare H2 O2 in the serum with that in the tears of these children. RESULTS: Compared with CT and VKC children treated with CsA, VKC untreated children had significantly higher values of hydrogen peroxide (H2 O2 ) in the serum and the tears. No significant differences were observed between CT and VKC treated with CsA. A significant correlation was found at the linear regression analysis between serum and tear H2 O2 levels. CONCLUSION: This study provides the first report attesting that patients with VKC have high oxidative stress; furthermore, it suggests that CsA could have an anti-inflammatory and antioxidant action that could be useful to prevent the poor VKC outcome.

Upper airway involvement in pediatric COVID-19.

The clinical spectrum of SARS-CoV-2 infection is mixed. It ranges from asymptomatic cases, medium-intensity forms with mild to moderate symptoms, to severe ones with bilateral lung involvement and respiratory distress, which can require transfer to ICUs and intubation. In most cases, the clinical picture is characterized by a persistent fever, cough, dyspnoea, expectoration, myalgias, arthralgias, headache, gastrointestinal symptoms, nasal congestion, and pharyngodynia. The spread of COVID-19 in Europe has highlighted an atypical presentation of disease involving upper airways and, above all, dysfunction of olfactory and gustatory senses. There is ample evidence that COVID-19 is significantly less severe in children than in adults. However, due to difficulties in assessing the disorder in children, especially among very young patients, the olfaction and gustatory dysfunctions remain open issues. This article sheds light on the upper airway involvement in pediatric COVID-19 subjects.

Assessing repeatability and reproducibility of Anterior Active Rhinomanometry (AAR) in children.

BACKGROUND: Repeatability and reproducibility are essential for clinicians for several purposes. Although discouraged, use of the Coefficient of Variation (CV) for assessing repeatability and reproducibility, rather than the Intraclass Correlation Coefficient (ICC), is still widespread. The aim of the present study was to highlight how using inappropriate indices may lead to misleading results, and this is done by simulation study and using real data on Anterior Active Rhinomanometry (AAR) in both healthy children and ones with rhinitis. METHODS: A simulation study was carried out to highlight how using inappropriate indices could be misleading. Then a comparison was made between CV and ICC to assess repeatability and reproducibility of AAR, for which previous studies have given underestimated results. AAR is recommended as the gold standard tool for measuring nasal resistance in clinical practice. RESULTS: A simulation study showed that the ICCs estimated from data generated assuming a true CV yielded results in agreement with estimated CVs; by contrast, if data were generated assuming a true ICC, CVs yielded conflicting results. For AAR, ICCs showed good repeatability, whereas CVs showed unacceptable repeatability. AUC and 95% CI for AAR showed good performance in predicting current symptoms of rhinitis in the overall study population. CONCLUSIONS: The present study focused on the importance of the choice of appropriate indices of repeatability and reproducibility, demonstrating the repeatability of AAR in both healthy children and ones with rhinitis. TRIAL REGISTRATION: ClinicalTrials.gov (ID: NCT03286049; Registration Date: September 15, 2017; Actual Study Start Date: January 10, 2018).

Oxidative stress and gut-derived lipopolysaccharides in children affected by paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections.

BACKGROUND: Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections syndrome (PANDAS) identifies patients with acute onset of obsessive-compulsive and tic disorders. The objective of this study was to evaluate serum NOX2 levels, as well as 8-iso-prostaglandin F2α (8-iso-PGF2α) and lipopolysaccharide (LPS) of PANDAS patients. METHODS: In this study we wanted to compare serum levels of soluble NOX2-dp (sNOX-2-dp), iso-PGF2α and LPS in 60 consecutive subjects, including 30 children affected by PANDAS and 30 controls (CT) matched for age and gender. Serum zonulin was used as intestinal permeability assay. RESULTS: Compared with CT, PANDAS children had increased serum levels of sNOX-2-dp, 8-iso-PGF2α and LPS. Bivariate analysis showed that serum sNOX2-dp was significantly correlated with LPS (Rs = 0.359; p = 0.005), zonulin (Rs = 0.444; p < 0.001) and 8-iso-PGF2α (Rs = 0.704; p < 0.001). Serum LPS significantly correlated with zonulin (Rs = 0.610; p < 0.001), and 8-iso-PGF2α (Rs = 0.591; p = 0.001). Finally, a multiple linear regression analysis showed that serum 8-iso-PGF2α and zonulin were the only independent variables associated with sNOX2-dp (R2 = 68%). CONCLUSION: This study shows that children affected by PANDAS have high circulating levels of sNOX2-dp, isoprostanes and of LPS that could be involved in the process of neuroinflammation.

Nasal reactivity evaluation in children with allergic rhinitis receiving grass pollen sublingual immunotherapy.

Background: The European Academy of Allergy and Clinical Immunology guidelines, strongly recommended allergen immunotherapy (AIT) as an effective treatment to achieve long-term clinical benefits and to modify the natural history of allergic diseases. Sublingual immunotherapy (SLIT) offers the possibility of home administration, which improves patient comfort and compliance. Objective: The primary outcome of this study was to assess the change in nasal reactivity after grass-pollen AIT treatment. Methods: This was a monocentric, prospective, observational study conducted in Rome from September 2016 to June 2018, in the Pediatric Department of Policlinico Umberto I. We enrolled children, ages between 6 and 12 years, with persistent allergic rhinitis (AR), sensitized to grass pollen. At the first visit (V0, September 2016), one group received the first dose of oral immunotherapy for grass-pollen spray buccal and the other group continued only standard therapy. All the patients had nasal specific immunoglobulin I (IgE) assay (Phl p1, Phl p5), active anterior rhinomanometry with a nasal provocation test (NPT), and spirometry. The patients attended two follow-up visits, in May 2017 (V1) and May 2018 (V2), with the same examinations as at V0. Results: During the treatment, we observed, in the treated group, a significant increase in the mean nasal flow compared with untreated children (p < 0.001). In the AIT group, we found an improvement of nasal function and only 21.05% of all the children in the active group with a positive NPT result at V2. In the control group, we found, at V2, a worsening of nasal function, with 89.47% of the children with a positive NPT result. Furthermore, we found a significant reduction of nasal specific IgE levels at the end of the observation period in the treated group. Conclusion: Analysis of our data provided evidence for a clinical effect of SLIT in inducing clinical changes and allergen tolerance in children with AR.

Early molecular biomarkers predicting the evolution of allergic rhinitis and its comorbidities: A longitudinal multicenter study of a patient cohort.

BACKGROUND: Pollen-related seasonal allergic rhinoconjunctivitis (SAR) is a very frequent pediatric disease in Westernized countries. Risk factors and disease phenotypes have been thoroughly examined in several cross-sectional studies. By contrast, only a few studies have examined disease evolution in patient cohorts. We investigated predictive biomarkers of disease evolution in a large cohort of children with SAR. METHODS: During 2015-2017 (follow-up), we re-examined 401 patients from those enrolled in 2009-2011 (baseline) by the "Panallergens in Pediatrics" study, a large multicenter survey of Italian children with SAR. Information on clinical history (standard questionnaire, AllergyCARD®; TPS, Italy) and skin prick tests for inhalant and foods extracts (ALK-Abelló, Hørsholm, Denmark) was acquired as at baseline visit. Evolution in clinical and sensitization data of patients was analyzed over time, as well as their association with the main baseline characteristics and atopy risk factors. RESULTS: The average age of participants was 10.4 ± 3.4 years at baseline and 16.2 ± 3.6 years at follow-up. SAR persisted in 93.3% of patients at follow-up and became more frequently associated with asthma (from 36.7% at baseline to 48.6% at follow-up) and oral allergy syndrome (OAS, from 23.4% to 37.7%). Compared to baseline, the prevalence of skin sensitization to some pollens (Phleum pratense, Corylus avellana, Platanus acerifolia, Artemisia vulgaris) and vegetables (hazelnut, wheat, and apple) significantly decreased at follow-up. Earlier onset of SAR and polysensitization at baseline were associated with incident asthma at follow-up. The presence at baseline of serum IgE to the following allergen molecules was identified as biomarkers of clinical evolution: (a) Phl p 1, for persistence of SAR; (b) Phl p 5, for persistence of both rhinitis and asthma; (c) Pru p 3, for new onset of asthma; (d) Bet v 1, for persistence of OAS. CONCLUSIONS: Seasonal allergic rhinoconjunctivitis is clinically heterogeneous in its evolution from childhood to adolescence. The detection of serum IgE to specific molecules (Phl p 1, Phl p 5, Bet v 1, Pru p 3) may be useful as biomarkers to predict SAR persistence and future onset of comorbidities, such as asthma and/or OAS.

When asthma and rhinitis coexist, could rhinitis reduce asthma control in children?

Background: Bronchial asthma and rhinitis are among the most common diseases in children and frequently coexist in the patient. The primary aim of anti-asthmatic therapy is disease control. Several questionnaires can be used in pediatrics to assess asthma control and the Children Asthma Control Test (C-ACT) is one of the most used. Objective: To evaluate the percentage of asthma control in our cohort of patients with asthma and correlate C-ACT with bronchial and nasal function tests. Methods: We enrolled all children ages between 5 and 11 years with persistent bronchial asthma, sensitized to dust mite, and who presented to our center during an 8-month period. All the children had skin-prick tests, spirometry, measurement of fractional exhaled nitric oxide levels, active anterior rhinomanometry, measurement of nasal nitric oxide level, and C-ACT. Results: Sixty patients were enrolled; 80% of these children had rhinitis. According to C-ACT, 31% of our patients had uncontrolled asthma. Nasal flow values were significantly lower in patients with uncontrolled asthma, who also had higher nasal inflammation. Conclusion: The disease is not controlled in a significant percentage of children with asthma. In patients with uncontrolled asthma, worse nasal flow was detected. These results supported the relationship between upper and lower airways, and highlighted the importance of performing nasal function tests in all patients with asthma, which could be useful to determine whether better control of asthma symptoms can be reached through an appropriate treatment of rhinitis.

Exploring the Role of Lactoferrin in Managing Allergic Airway Diseases among Children: Unrevealing a Potential Breakthrough.

The prevalence of allergic diseases has dramatically increased among children in recent decades. These conditions significantly impact the quality of life of allergic children and their families. Lactoferrin, a multifunctional glycoprotein found in various biological fluids, is emerging as a promising immunomodulatory agent that can potentially alleviate allergic diseases in children. Lactoferrin's multifaceted properties make it a compelling candidate for managing these conditions. Firstly, lactoferrin exhibits potent anti-inflammatory and antioxidant activities, which can mitigate the chronic inflammation characteristic of allergic diseases. Secondly, its iron-binding capabilities may help regulate the iron balance in allergic children, potentially influencing the severity of their symptoms. Lactoferrin also demonstrates antimicrobial properties, making it beneficial in preventing secondary infections often associated with respiratory allergies. Furthermore, its ability to modulate the immune response and regulate inflammatory pathways suggests its potential as an immune-balancing agent. This review of the current literature emphasises the need for further research to elucidate the precise roles of lactoferrin in allergic diseases. Harnessing the immunomodulatory potential of lactoferrin could provide a novel add-on approach to managing allergic diseases in children, offering hope for improved outcomes and an enhanced quality of life for paediatric patients and their families. As lactoferrin continues to capture the attention of researchers, its properties and diverse applications make it an intriguing subject of study with a rich history and a promising future.

Attitude to food supplement use: a survey promoted by the Italian Society of Pediatric Allergy and Immunology.

Food supplements are defined as foodstuffs the purpose of which is to supplement the normal diet and which are concentrated sources of nutrients or other substances with a nutritional or physiological effect, often referred to as nutraceuticals, may exert benefit to the human body. Their use is increasing worldwide, including Europe and in Italy. However, some doctors are skeptical about their effectiveness and safety. This reluctance may depend on poor knowledge of the mechanisms of action and clinical evidence in literature. The Italian Society of Pediatric Allergy and Immunology (SIAIP) promoted the institution of an ad hoc Committee. The first initiative performed by this Committee was the administration of a questionnaire to the members of SIAIP.The results of this survey provided interesting results. Most pediatricians know the food supplement concept but frequently need help understanding the mechanisms of action. Most prescribe food supplements, mainly for preventing infections or enhancing immune defense. In addition, they prefer to use food supplements as cycles or add-on therapy. Finally, most participants like to attend events on this issue and contribute to new evidence through trials.In conclusion, this survey underscores the relevance of food supplement issues and attests to interest in this topic. However, there is a need to provide information and promote studies on this matter.

Subcutaneous Immunotherapy (SCIT) with the New Polymerized Molecular Allergoid Alt a1: A Pilot Study in Children with Allergic Rhinitis Sensitized to Alternaria Alternata.

BACKGROUND: We followed the effects of a new SCIT with a chemically polymerized allergen Alt a1, evaluating the trend of clinical and functional parameters in an observational-prospective study. METHODS: 42 children with AR and intermittent asthma sensitized to A.A.: 17 patients started SCIT (Modigoid®), and 25 continued symptomatic therapy. At the initial visit (T0), all patients performed total IgE (tIgE) and specific IgE (sIgE) for Alt a1, nasal nitric oxide (nFeNo), nasal cytology, anterior active rhinomanometry (AAR) and spirometry. After 24 months (T1), they repeated the same procedures as in T0. RESULTS: Patients treated with Modigoid presented a statistically significant (p < 0.001) reduction of nFeNO (T0:1651.06 ± 149.18; T1: 1394.12 ± 108.98), tIgE (T0: 311.48 ± 144.18; T1: 164.73 ± 50.69), sIgE for Alt a1 (T0: 28.59 ± 12.69; T1: 19.54 ± 7.37), an improvement of nasal airflow (T0: 71.62 ± 8.66; T1: 95.12 ± 5.91), nasal eosinophils (T0: 20.59 ± 2.35; T1: 14.88 ± 1.65) and FEV1 (T0: 95.58 ± 7.91; T1: 116.64 ± 5.94). CONCLUSIONS: The new SCIT for Alt a1 significantly improves AR symptoms from a subjective, objective point of view and laboratory and functional parameters.

Kiwifruit's Allergy in Children: What Do We Know?

Kiwifruit allergy is an emerging pathological condition in both general and pediatric populations with a wide range of symptoms linked to variable molecular patterns, justifying systemic and cross-reactions with other allergens (i.e., latex, pollen, and fruit). Skin prick test (SPT), specific serum IgE (Act d 1, Act d 2, Act d 5, Act d 8, and Act d 10) directed against five out of thirteen molecular allergens described in the literature, and oral test challenge with kiwifruit are available for defining diagnosis. The management is similar to that of other food allergies, mostly based on an elimination diet. Although kiwi allergy has been on the rise in recent years, few studies have evaluated the clinical characteristics and methods of investigating this form of allergy. Data collected so far show severe allergic reaction to be more frequent in children compared to adults. Therefore, the aim of this review is to collect the reported clinical features and the available association with specific molecular patterns of recognition to better understand how to manage these patients and improve daily clinical practice.

Evaluation of nasal airway resistance in a cohort of children with primary snoring and maxillary deficiency.

BACKGROUND: The aim of this study was to test whether rapid palatal expansion is effective to improve nasal airway patency in a sample of pediatric patients with primary snoring. METHODS: A group of 21 subjects, 11 girls (52%) and 10 boys (48%), with a mean age of 7.1 years (SD=1.3; range 4-9 years) were treated with a rapid maxillary expansion (RME) device. Nasal airway resistance was assessed via rhinomanometric exam before (pre-) and 6 months after (post-) the rapid palatal expansion treatment. RESULTS: Data analysis showed a statistically significant increase in the mean scores of the results of the rhinomanometric exam between the pre- and post-measurements with a significant reduction in total inspiratory and expiratory air resistance values after rapid palatal expansion. CONCLUSIONS: Our results show that RME treatment is associated with an improvement in nasal airway resistance due to a substantial reduction in nasal resistance associated with the orthopedic action of the orthodontic device.

Reply to Özdemir, Ö. Allergic Disease with Selective IgA Deficiency. Comment on "Cinicola et al. The Allergic Phenotype of Children and Adolescents with Selective IgA Deficiency: A Longitudinal Monocentric Study. J. Clin. Med. 2022, 11, 5705".

We carefully read the correspondence [...].