Background/Objectives: Bronchiolitis is the leading cause of hospitalization in infants under 12 months. While often self-limiting, a subset of cases evolves into severe disease requiring intensive care. This study aimed to identify risk factors for severe bronchiolitis in two consecutive respiratory syncytial virus (RSV) seasons (before and after the introduction of nirsevimab) in Southern Italy. Methods: A retrospective, multicenter cohort study was conducted on all infants ≤12 months hospitalized with bronchiolitis from October 2023 to March 2025. Patients were categorized by disease severity: those requiring Sub-Intensive or Intensive Care (IC group) and others (n-IC group). Demographic and clinical data, virological testing, and therapeutic interventions were analyzed. Multivariable logistic regression was used to identify independent risk factors for severe disease. Results: Among 1056 hospitalized infants, 10.5% required intensive care. RSV was detected in 73.5% of tested patients and was significantly associated with severe outcomes. Independent risk factors for IC admission included younger age (<3 months), comorbidities, and RSV infection. A 33% reduction in bronchiolitis admissions was observed in the second season (post-nirsevimab), although the rate of severe cases remained stable (about 10% in both seasons). Conclusions: Younger age, comorbidities, and RSV infection are significant predictors of severe bronchiolitis. Although overall admissions decreased post-nirsevimab, severe cases persisted. These findings underscore the need for targeted preventive strategies and highlight the potential role of intermediate care approaches in managing bronchiolitis severity.

Background: Acute otomastoiditis (AOM) may occasionally progress to severe intracranial complications in children. While immunological and microbiological factors have been studied, the role of temporal bone anatomical variants remains less well-defined. The aim of this study is to investigate the prevalence of anatomical variants in pediatric patients with acute complicated otomastoiditis (ACOM) compared to those with uncomplicated ones (AUOM) and healthy controls (HC) and assess their potential association with intracranial complication patterns. Methods: This retrospective, single-center study reviewed clinical and neuroradiological data of patients aged 0–16 years admitted for AOM between 2018 and 2025. ACOM patients were compared to AUOM and HC groups (the latter undergoing neuroimaging for minor head trauma). Two experienced neuroradiologists evaluated imaging to identify anatomical variants involving the following: (1) sigmoid sinus and emissary veins; (2) tegmen tympani; and (3) mastoid pneumatization. Statistical analyses assessed prevalence differences across groups. Results: Among 282 AOM patients, 58 had intracranial complications. Anatomical variants were significantly more frequent in ACOM patients versus both AUOM and HC (p < 0.01). In this subgroup, vascular anatomical variants were notably associated with vascular or combined (vascular and infectious) complications; tegmen tympani and mastoid pneumatization variants showed no significant subgroup associations. Conclusion: Anatomical variants, particularly vascular anomalies of the sigmoid sinus and emissary veins, appear to increase pediatric AOM patients’ susceptibility to intracranial complications. Recognition of these configurations through early neuroimaging could aid risk stratification and improve diagnostic and therapeutic strategies.

Background: Acute mastoiditis is the most frequent suppurative complication of acute otitis media in children. AM can lead to both extracranial complications and intracranial complications. Recent studies suggest an increase in cases after the COVID-19 pandemic. Objective: To compare the epidemiological and clinical characteristics of pediatric patients diagnosed with acute mastoiditis admitted to Santobono-Pausilipon Children’s Hospital before and after COVID-19. Methods: We conducted a retrospective study including all patients aged 0–16 years with AM admitted to our hospital between January 2017 and December 2024. Patients were stratified into three groups: pre-COVID-19: 1 January 2017–28 February 2020; COVID-19: 1 March 2020–31 December 2021; and post-COVID-19: 1 January 2022–31 December 2024. Demographic data, clinical presentations, complications, laboratory findings, and treatment modalities were analyzed and compared between groups. Results: A total of 276 children (153 males and 123 females; median age: 49 months, age range: 1–177 months) were included. Hospital admissions for AM increased in the post-COVID-19 period, reaching more than a threefold increase in 2024 compared with the pre-COVID-19 years. Similar to the overall number of AM cases, the absolute number of complications, especially IC, such as thrombosis and empyema, increased. The rate of surgical procedures increased during the post-COVID-19 period, with an overall increase of 88.5%. Both the duration of antibiotic therapy and hospital stay were significantly longer in the post-COVID-19 period. Conclusions: The COVID-19 pandemic has been associated with epidemiological and clinical changes in pediatric AM patients. These findings highlight the need for effective preventive strategies, including enhanced vaccination coverage and the promotion of early diagnosis. Additionally, implementing standardized clinical protocols could support more efficient and consistent management, reducing hospital stays and recurrence rates.

Background: Gallbladder involvement during acute hepatitis A virus (HAV) infection is generally considered an uncommon extrahepatic manifestation, although recent reports suggest it may be underrecognized. We evaluated the prevalence, clinical characteristics and outcomes of gallbladder abnormalities in a multicenter cohort of children hospitalized with acute HAV infection during an Italian outbreak. Methods: We conducted a multicenter observational study, including consecutive children with laboratory-confirmed acute HAV infection admitted to 4 tertiary pediatric hospitals between January and May 2026. Clinical, laboratory and ultrasonographic findings were collected. All patients underwent abdominal ultrasonography during the acute phase of illness. Results: Thirty-three children were included. Gallbladder abnormalities compatible with acute acalculous cholecystitis were identified in 18 patients (54.5%), including marked gallbladder wall thickening (>7 mm) in 8. Children with gallbladder involvement did not exhibit more severe clinical manifestations or greater biochemical impairment than those without ultrasonographic abnormalities. Serum bile acids were markedly elevated in most tested patients but were not associated with gallbladder abnormalities. All patients were managed conservatively, and none developed gallbladder perforation, empyema, gangrene or required surgical intervention. Complete clinical recovery with progressive normalization of laboratory and ultrasonographic findings was observed in all cases. Conclusions: Systematic ultrasonography identified gallbladder involvement in more than half of children hospitalized with acute HAV infection, suggesting that this manifestation may be substantially underrecognized rather than truly rare. Despite frequent ultrasonographic abnormalities, the clinical course was uniformly benign, supporting conservative management in the absence of complications.

Many pediatric patients with severe bacterial infection (SBI) present with a compromised general clinical picture. Early identification of the infectious and inflammatory state can improve clinical outcomes. Although microbiological culture remains the gold standard for diagnosis, its delayed results highlight the need for early biomarkers to improve clinical decision-making and patient outcomes. During infection, the acute phase response alters lipid metabolism, compromising cholesterol efflux. In this study, we characterized the serum lipid profile and HDL subclasses in 63 children with SBI at hospital admission (T0) and discharge (T1), comparing them with 63 age- and sex-matched healthy subjects. At T0, we found a significant reduction in serum total cholesterol, LDL cholesterol, and HDL cholesterol in subjects with SBI compared to controls. Interestingly, at a cut-off value of 41.5 mg/dL, HDL cholesterol discriminated the two groups with a sensitivity of 76% and a specificity of 86% for SBI. At T1, total and LDL cholesterol increased, while HDL cholesterol remained unchanged. Moreover, we observed at T1 a clear remodeling of HDL classes, with a significant decrease in large HDL with pro-inflammatory activity and an increase in the intermediate and small HDL with anti-inflammatory activity, compared to time T0. This study proposes serum HDL cholesterol as a candidate biomarker and highlights the role of HDL cholesterol and its classes in inflammatory and immune regulation in systemic bacterial infection, potentially identifying patients who could benefit from HDL-based therapies.