Background: Eosinophilic esophagitis (EoE) is a chronic immune-mediated esophageal disease frequently associated with atopic conditions in children. However, the extent and nature of this association remain unclear. We retrospectively estimated the prevalence of atopic conditions in a paediatric population with EoE and we prospectively screened children with aeroallergen sensitisation to estimate the prevalence of EoE. Methods: We retrospectively described atopic profiles of paediatric patients previously diagnosed with EoE. We prospectively recruited children with confirmed aeroallergen sensitisation, who completed a screening questionnaire targeting symptoms suggestive of EoE. Patients with positive screening results were referred to a paediatric gastroenterologist for further evaluation, including esophagogastroduodenoscopy with biopsy when indicated, to confirm or exclude EoE. Results: In the retrospective cohort of 83 patients (median age: 9.4 years), 69.9% were sensitised to aeroallergens, 61.4% had asthma, 57.8% had allergic rhinitis (AR), 41.0% had atopic dermatitis and 43.4% had IgE-mediated food allergies. Neither the severity of these conditions nor the number of concurrent atopic diseases correlated with peak eosinophil counts on esophageal biopsies. In the prospective cohort, 168 aeroallergen-sensitised children (median age: 9.6 years) were enrolled. Of these, 56 (33.3%) had positive screening questionnaires and 3 were subsequently diagnosed with EoE. Notably, AR—regardless of its severity—was associated with an increased risk of EoE-related symptoms. Conclusion: A high prevalence of aeroallergen sensitisation was observed among children with EoE. We recommend routine screening of patients with respiratory sensitisation—especially those with AR—using a brief questionnaire, followed by a paediatric gastroenterologist consultation for EoE evaluation.

Hereditary angioedema (HAE) is a rare, life-threatening genetic disorder characterized by acute, recurrent and unpredictable episodes of cutaneous or submucosal angioedema, mediated by bradykinin, due to C1 inhibitor (C1INH) abnormalities in the vast majority of cases. The epidemiology of the disease is poorly documented in children. Clinical manifestations usually appear during childhood or early adolescence. Classical signs, preceded by prodromal symptoms in 50 % of cases, include transient, localized, non-pitting, non-pruritic swelling of deep dermal/subcutaneous or mucosal/submucosal tissues, leading to oedema of the extremities, face, lips, tongue, trunk and genitals, recurring gastrointestinal symptoms and laryngeal edema possibly causing asphyxiation and death. Diagnosis is often delayed due to low awareness in the medical community, and particularly challenging in case of isolated abdominal crises or atypical presentation and in neonates or infants. It relies on biological tests (measurement of serum/plasma levels of C1INH function, C1INH protein, and C4), genetic testing in selected cases, and imaging for differential diagnosis of acute abdominal crises. Main differential diagnosis for peripheral oedema is mast cell-mediated oedema that accounts for 95 % of angioedema in clinical practice. Quality of life can be significantly impaired. Disease management includes treatment of attacks, short-term and long-term prophylaxis, psychological support, avoidance of triggers, patients’ and parents’ education and coordination of all stakeholders, ideally within a specialized healthcare network. New plasma kallikrein inhibitors, namely lanadelumab (subcutaneous route) and berotralstat (oral route) have facilitated long-term prophylaxis thanks to improved usability.

Background : Several major sensitization profiles have been described in children with asthma, but it remains unclear how these profiles relate to asthma phenotypes. The aim of this study was to determine allergenic sensitization profiles in a megacity cohort (SAMP). Methods : This was a cross-sectional analysis performed from 2011 to 2015 including preschool and school-age children with severe and moderate asthma from the SAMP cohort. We performed ALEX multiplex array and carried out cluster analysis. Results: Data from 367 children were analysed: 224 of preschool age and 143 of school age, respectively 84 (38%) and 114 (80%) presented at least one allergic sensitization. At preschool age, three clusters were identified: Cluster 1, Few sensitizations to inhaled allergen molecular families and non-type 2 (T2) inflammation (n=61); Cluster 2, Predominant sensitization to HDM molecular families. (n=16); Cluster 3, Severe asthma with multiple sensitizations to inhaled and food allergen molecular families (n=7). At school age, five clusters were identified: Cluster 1, Few sensitizations to inhaled allergen molecular families and non-T2 inflammation (n=43); Cluster 2, Predominant sensitization to HDM molecular families (n=31); Cluster 3, Predominant sensitization to PR-10 family (n=25); Cluster 4, Severe asthma with predominant sensitization to tropomyosin family (n=11); Cluster 5, Severe asthma with multiple sensitizations to inhaled and food allergen molecular families (n=4). Conclusion: These results underline the heterogeneity of sensitization profiles in severe allergic childhood asthma. The most severe asthma phenotypes were associated with multiple sensitizations to both inhaled and food allergen molecular families as expected, and to the tropomyosin molecular family, a novel finding.