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.

Background: Probiotics may prevent the allergic response development due to their anti-inflammatory and immunomodulatory effects. The aim of this study is to determine if the prophylactic treatment with a mixture of Bifidobacterium animalis subsp. Lactis BB12 and Enterococcus faecium L3 would reduce symptoms and need for drug use in children with allergic rhinitis (AR). Methods: The study included 250 children aged from 6 to 17 years, affected by AR. Patients were randomly assigned to the intervention group (150) or to the placebo group (100). Patients in the intervention group, in addition to conventional therapy (local corticosteroids and/or oral antihistamines), were treated in the 3 months preceding the onset of symptoms related to the presence of the allergen to which the children were most sensitized, with a daily oral administration of a probiotic mixture containing the Bifidobacterium animalis subsp. Lactis BB12 DSM 15954 and the Enterococcus faecium L3 LMG P-27496 strain. We used Nasal Symptoms Score (NSS) to evaluate AR severity before and after the treatment with probiotics or placebo. Results: the patients in the intervention group had a significant reduction in their NSS after probiotic treatment (p-value = 2.2 × 10⁻¹⁰. Moreover, for the same group of patients, we obtained a significant reduction in the intake of pharmacological therapy. In particular, we obtained a reduction in the use of oral antihistamines (p-value = 2.2 × 10⁻¹⁶), local corticosteroids (p-value = 2.2 × 10⁻¹³), and of both drugs (p-value 1.5 × 10⁻¹⁵). Conclusions: When administered as a prophylactic treatment, a mixture of BB12 and L3 statistically decreased signs and symptoms of AR and reduced significantly the need of conventional therapy.

Background: The role of allergic sensitization seems to be protective against SARS CoV2 infection. The aim of this study was to evaluate, using online surveys, the impact of COVID-19 on Italian allergic children, comparing the prevalence of AR and asthma symptoms between the first and second pandemic wave. Methods: Both surveys were emailed to Italian pediatricians in April 2020 (first survey) and in March 2021 (second survey). The first one was related to the impact of COVID-19 and the most frequently reported symptoms. The second one was superimposed on the previous one, taking into account some additional aspects in the management of disease. Results: A total of 99 pediatricians participated in the first survey and 267 in the second one. The first survey showed that, asthma and allergic rhinoconjunctivitis prevalence was mostly between 0 and 20% throughout the country. The second survey showed a lower prevalence of both diseases nationwide in comparison to the first one. Comparing the two surveys, statistically significant differences were reported only in the distribution of asthma prevalence in Southern Italy while no differences were highlighted in the North and in the Center. Finally regarding allergic rhinoconjunctivitis prevalence, no differences were noticed nationwide. Conclusions: Allergic rhinoconjunctivitis and asthma, if under control, did not represent risk factors for the susceptibility to SARS CoV2. Therefore, it is strongly recommended to continue therapies during COVID-19 outbreak, according to the international guidelines. However, being COVID-19 a new disease, actual knowledge will undergo continuous improvements over time.

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.

The persistence of symptoms after recovery from Coronavirus 2019 (COVID-19) is defined as long COVID, an entity that had occurred among adults but which is not yet well characterized in pediatric ages. The purpose of this work was to present some of the data from a survey addressed to Italian pediatricians concerning the impact of long-COVID among children who recovered from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. The questionnaire was designed and pre-tested in February 2021 by a working group of experts from the Italian Pediatric Society for Allergy and Immunology (SIAIP). The survey was emailed once in March 2021 to a sample of Italian pediatricians. A total 267 Italian pediatricians participated in our survey. According to most pediatricians (97.3%), the persistence of symptoms is found in less than 20% of children. Specifically, with regard to the symptoms that persist even after swab negativization, fatigue was the most mentioned one (75.6%). Long-COVID would seem to be a phenomenon of limited occurrence in pediatric ages, affecting less than 20% of children. Among all of the symptoms, the one that was most prevalent was fatigue, a pathological entity that is associated with many viral diseases.

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).