Acute hemorrhagic edema of infancy: 20-year experience from an Italian tertiary referral center.

PURPOSE: Data on acute hemorrhagic edema of infancy (AHEI) are derived from small case series or case reports. We report a 20-year experience at a national referral center. METHODS: We performed a single-center retrospective study including patients who were diagnosed with AHEI from January 1, 2004, to June 30, 2023. RESULTS: We identified 21 patients (57.1% females) with a median age of 18 months (range 7-33 months). Thirteen (61.9%) patients were admitted to the pediatric ward, the remaining eight (38.1%) presented to the emergency department and were discharged for outpatient management. The median length of hospitalization was 5 days (range 3-9 days). Twenty patients (95.2%) had prodromal symptoms. The most common cutaneous findings were targetoid purpuric plaques. The lesions were most localized on the face (13, 61.9%) and on the upper limbs (18 patients, 85.7%). Sixteen (76%) patients presented with nonpitting and tender edema, localized on the feet (9/16, 56%) and hands (6/16, 37.5%). Systemic involvement was rare, and no patients experienced complications or sequelae. Twelve (57.1%) patients underwent infectious disease investigations, with positive results in only four (33.3%). None of the patients diagnosed after the SARS-CoV-2 outbreak (March 2020) had positive nasopharyngeal swabs for the virus. For the 13 patients who were admitted to the pediatric ward, the median length of hospitalization was five days (3-9 days). CONCLUSIONS: The 21-patient single-center cohort of children affected by AHEI confirmed a generally benign course of AHEI, despite a 62% rate of hospitalization.

To switch or to swap? Evidence from a meta-analysis for the best treatment approach in childhood chronic uveitis resistant to the I anti-TNF.

Objective: Since adalimumab approval in childhood chronic non-infectious uveitis (cNIU), the prognosis has been dramatically changed, but the 25 % failed to achieve inactivity. There is not accordance if it is better to switch to another anti-TNF or to swap to another category of biologic. Thus, we aim to summarize evidence regarding the best treatment of cNIU refractory to the first anti-TNF. Methods: A systematic literature review and meta-analysis, according to PRISMA Guidelines, was performed(Jan2000-Aug2023). Studies investigating the efficacy of treatment in cNIU refractory to the first anti-TNF were considered for inclusion. The primary outcome was the improvement of intraocular inflammation according to SUN. A combined estimation of the proportion of children responding to switch or swap and for each drug was performed. Results: 23 articles were eligible, reporting 150 children of whom 109 switched anti-TNF (45 adalimumab, 49 infliximab, 9 golimumab) and 41 swapped to another biologics (31 abatacept, 8 tocilizumab and 1 rituximab). The proportion of responding children was 46 %(95 % CI 23-70) for switch and 38 %(95 % CI 8-73) for swap (χ20.02, p = 0.86). Instead analysing for each drug, the proportion of responding children was the 24 %(95 % CI 2-55) for adalimumab, 43 %(95 % CI 2-80) for abatacept, 79 %(95 % CI 61-93) for infliximab, 56 %(95 % CI 14-95) for golimumab and 96 %(95 % CI 58-100) for tocilizumab. We evaluated a superiority of tocilizumab and infliximab compared to the other drugs(χ2 27.5 p < 0.0001). Conclusion: Although non-conclusive, this meta-analysis suggests that, after the first anti-TNF failure, tocilizumab and infliximab are the best available treatment for the management of cNIU.

Uveitis as predictor of disease flare after the first anti-TNF withdrawal in oligoarticular and polyarticular juvenile idiopathic arthritis: a multicentric Italian experience.

OBJECTIVES: TNF inhibitors (TNFi) have dramatically changed the prognosis of juvenile idiopathic arthritis (JIA), but it is not clear how and when stop therapy. We aim to describe a multicentric cohort of JIA treated with adalimumab or etanercept who discontinued the treatment for persistent inactivity and to identify factors associated with relapse. METHODS: In a multicentric Italian retrospective cohort study, medical records of patients with oligoarticular and polyarticular JIA were evaluated if they stopped therapy for persistent inactivity after the first TNFi. RESULTS: 136 patients were enrolled (102 female, median age at onset 3 years (range 1-15), of whom 55.9% had oligoJIA, 40.4% uveitis and 72.8% ANA positivity. Adalimumab (59.3%) and etanercept (40.7%) were started at a median age of 6 years (range 1-16), TNFi were discontinued after a median time of 30 months (range 6-90), increasing the interval (76.5%), reducing the dose (18.4%) and abrupt discontinuation (16.9%). 79.4% of patients relapsed after a median time of 5 months (range 0.5-66). Patients with uveitis relapsed earlier (log rank χ² 16.4 p<0.0001), while patients who lengthened the interval of administration showed a later relapse (log rank χ² 6.95 p=0.008). Uveitis (HR 2.11 CI 1.34-3.31), age at onset (HR 0.909 CI 0.836-0.987), duration of tapering (HR 0.938 CI 0.893-0.985) and to have a persistent OligoJIA (HR 0.597 CI 0.368-0.968) are significant predictors of disease relapse (Mantel-Cox χ² 34.23 p<0.001). CONCLUSIONS: Younger age at onset, uveitis, duration of tapering, and not-persistent OligoJIA seem to be independent risk factors for earlier relapse after the first TNFi withdrawal.

The HyperPed-COVID international registry: Impact of age of onset, disease presentation and geographical distribution on the final outcome of MIS-C.

OBJECTIVES: The aim of the study was to establish an international multicenter registry to collect data on patients with Multisystem Inflammatory Syndrome in Children (MIS-C), in order to highlight a relationship between clinical presentation, age of onset and geographical distribution on the clinical outcome. STUDY DESIGN: Multicenter retrospective study involving different international societies for rare immunological disorders.1009 patients diagnosed with MIS-C between March and September 2022, from 48 centers and 22 countries were collected. Five age groups (<1, 1-4, 5-11, 12-16, >16 years) and four geographic macro-areas, Western Europe, Central-Eastern Europe, Latin America, Asian-African resource-limited countries (LRC), were identified. RESULTS: Time to referral was significantly higher in LRC. Intensive anti-inflammatory treatment, including biologics, respiratory support and mechanic ventilation were more frequently used in older children and in European countries. The mortality rate was higher in very young children (<1 year), in older patients (>16 years of age) and in LRC. Multivariate analysis identified the residence in LRC, presence of severe cardiac involvement, renal hypertension, lymphopenia and non-use of heparin prophylaxis, as the factors most strongly associated with unfavorable outcomes. CONCLUSIONS: The stratification of patients by age and geographic macro-area provided insights into the clinical presentation, treatment and outcome of MIS-C. The mortality and sequelae rates exhibited a correlation with the age and geographical areas. Patients admitted and treated in LRC displayed more severe outcomes, possibly due to delays in hospital admission and limited access to biologic drugs and to intensive care facilities.

Thrombotic manifestations in pediatric Behcet syndrome: A multicenter comparative study from the EUROFEVER registry.

INTRODUCTION: Vascular events account for a considerable burden of morbidity and mortality in Behçet syndrome (BS). Thrombosis occurs in 1.8-21 % pediatric BS patients, even if the real prevalence is still largely unknown. OBJECTIVES: To report clinical features and outcomes of pediatric BS patients with thrombosis and to compare the demographic and clinical characteristics of BS patients with and without thrombosis. METHODS: Retrospective data collection of BS patients with thrombosis (T+) included in the EUROFEVER registry. BS patients without thrombosis (T-), belonging to the same rheumatology units, were matched in a 2:1 ratio. RESULTS: 37 T+ were compared to 74 T- patients. At onset, ICBD criteria fulfillment was higher in the T- group (p = 0.015). Caucasian patients were more often T-, Turkish patients were more frequent in T+ group (p = 0.002). At onset, pustulosis was most frequently observed in the T- (p < 0.001) as well as gastrointestinal symptoms (p < 0.001) and ocular involvement (p = 0.022). Neurological symptoms were more often described in T+ (p = 0.034). As for T+, thrombosis was reported at BS presentation in 8/37 (21.6 %). For the T + e patients who developed thrombosis later, oral aphthosis (p = 0.003), genital aphthosis (p = 0.014) were more frequently observed at BS onset, while pustulosis (p = 0.005) and fever (p = 0.043) coexisted with thrombosis. Thrombosis was mainly venous (26/37,70.3 %), involving the cerebral sinuses (21/37, 56.8 %). After thrombosis, 35/37 (94.6 %) T+ patients received an immunomodulatory treatment compared with 16/29 (55.2 %) pre-thrombosis. A recurrence was reported in 6/31(19.4 %). CONCLUSION: Thrombosis was reported at BS presentation in one fifth of cases. Pustolosis and fever were more frequently concomitant to thrombosis. Sinus veins were the most frequent site.

Prevalence and clinical features of chronic uveitis in pediatric inflammatory bowel diseases: A nationwide study.

Inflammatory bowel diseases (IBD) encompass a group of chronic inflammatory disorders primarily affecting the gastrointestinal tract but capable of impacting various organs, including the eye, with uveitis being the most common ocular condition. We assessed uveitis prevalence and clinical features in a nationwide cohort of pediatric IBD. Among 4229 cases, six patients (four Crohn's disease, one ulcerative colitis, and one unclassified IBD) were identified, resulting in an overall prevalence rate of 141.8 per 100,000 patients. Uveitis onset varied: two before IBD, two after, and two concomitantly. Symptomatic uveitis occurred in 2/6 patients, with anterior involvement in all cases. Median follow-up was 3 years (interquartile range 2-4.75 years). At the last follow-up, 5/6 patients exhibited quiescent IBD, while 4/6 had inactive uveitis. One patient had ocular complications. Uveitis is a rare but potentially complicating manifestation of pediatric IBD.

Defining Criteria for Disease Activity States in Systemic Juvenile Idiopathic Arthritis Based on the Systemic Juvenile Arthritis Disease Activity Score.

OBJECTIVE: Our objective was to develop and validate cutoff values in the systemic Juvenile Arthritis Disease Activity Score 10 (sJADAS10) that distinguish the states of inactive disease (ID), minimal disease activity (MDA), moderate disease activity (MoDA), and high disease activity (HDA) in children with systemic juvenile idiopathic arthritis, based on subjective disease state assessment by the treating pediatric rheumatologist. METHODS: The cutoff definition cohort was composed of 400 patients enrolled at 30 pediatric rheumatology centers in 11 countries. Using the subjective physician rating as an external criterion, six methods were applied to identify the cutoffs: mapping, calculation of percentiles of cumulative score distribution, the Youden index, 90% specificity, maximum agreement, and receiver operating characteristic curve analysis. Sixty percent of the patients were assigned to the definition cohort, and 40% were assigned to the validation cohort. Cutoff validation was conducted by assessing discriminative ability. RESULTS: The sJADAS10 cutoffs that separated ID from MDA, MDA from MoDA, and MoDA from HDA were ≤2.9, ≤10, and >20.6, respectively. The cutoffs discriminated strongly among different levels of pain, between patients with and without morning stiffness, and among patients whose parents judged their disease status as remission or persistent activity or flare or were satisfied or not satisfied with current illness outcome. CONCLUSION: The sJADAS cutoffs revealed good metrologic properties in both definition and validation cohorts and are therefore suitable for use in clinical trials and routine practice.

Convergence and divergence in Kawasaki disease and multisystem inflammatory syndrome in children: results from the COVASAKI survey.

OBJECTIVES: To compare Kawasaki disease (KD) and multisystem inflammatory syndrome (MIS-C) in children. METHODS: Prospective collection of demographics, clinical and treatment data. Assessment of type 1 interferon (IFN) score, CXCL9, CXCL10, Interleukin (IL)18, IFNγ, IL6, IL1b at disease onset and at recovery. RESULTS: 87 patients (43 KD, 44 MIS-C) were included. Age was higher in MIS-C compared to KD group (mean 31±23 vs. 94±50 months, p<0.001). Extremities abnormalities (p=0.027), mucosal involvement (p<0.001), irritability (p<0.001), gallbladder hydrops (p=0.01) and lymphadenopathy (p=0.07) were more often recorded in KD. Neurological findings (p=0.002), gastrointestinal symptoms (p=0.013), respiratory involvement (p=0.019) and splenomegaly (p=0.026) were more frequently observed in MIS-C. Cardiac manifestations were higher in MIS-C (p<0.001), although coronary aneurisms were more frequent in KD (p=0.012). In the MIS-C group, the multiple linear regression analysis revealed that a higher IFN score at onset was related to myocardial disfunction (p<0.001), lymphadenopathy (p=<0.001) and need of ventilation (p=0.024). Both CXCL9 and CXCL10 were related to myocardial disfunction (p<0.001 and p=0.029). IL18 was positively associated to PICU admission (0.030) and ventilation (p=004) and negatively associated to lymphadenopathy (0.004). IFNγ values were related to neurological involvement and lymphadenopathy (p<0.001), IL1b to hearth involvement (0.006). A negative correlation has been observed between IL6 values, heart involvement (p=0.013) and PICU admission (p<0.001). CONCLUSIONS: The demographic and clinical differences between KD e MIS-C cohorts confirm previous reported data. The assessment of biomarkers levels at MIS-C onset could be useful to predict a more severe disease course and the development of cardiac complications.

Severe A(H1N1)pdm09 influenza acute encephalopathy outbreak in children in Tuscany, Italy, December 2023 to January 2024.

A severe outbreak of influenza A(H1N1pdm09) infection in seven children (median age: 52 months) occurred between December 2023 and January 2024 in Tuscany, Italy. Clinical presentation ranged from milder encephalopathy to acute necrotizing encephalopathy (ANE) with coma and multiorgan failure; one child died. This report raises awareness for clinicians to identify and treat early acute encephalopathy caused by H1N1 influenza and serves as a reminder of severe presentations of influenza in young children and the importance of vaccination.

A practical approach to uveitis screening in children with juvenile idiopathic arthritis.

BACKGROUND: Juvenile idiopathic arthritis (JIA)-associated uveitis typically presents as a silent chronic anterior uveitis and can lead to blindness. Adherence to current screening guidelines is hampered by complex protocols which rely on the knowledge of specific JIA characteristics. The Multinational Interdisciplinary Working Group for Uveitis in Childhood identified the need to simplify screening to enable local eye care professionals (ECPs), who carry the main burden, to screen children with JIA appropriately and with confidence. METHODS: A consensus meeting took place in January 2023 in Barcelona, Spain, with an expert panel of 10 paediatric rheumatologists and 5 ophthalmologists with expertise in paediatric uveitis. A summary of the current evidence for JIA screening was presented. A nominal group technique was used to reach consensus. RESULTS: The need for a practical but safe approach that allows early uveitis detection was identified by the panel. Three screening recommendations were proposed and approved by the voting members. They represent a standardised approach to JIA screening taking into account the patient's age at the onset of JIA to determine the screening interval until adulthood. CONCLUSION: By removing the need for the knowledge of JIA categories, antinuclear antibody positivity or treatment status, the recommendations can be more easily implemented by local ECP, where limited information is available. It would improve the standard of care on the local level significantly. The proposed protocol is less tailored to the individual than the 'gold standard' ones it references and does not aim to substitute those where they are being used with confidence.

Safety and effectiveness of abatacept in juvenile idiopathic arthritis: results from the PRINTO/PRCSG registry.

OBJECTIVE: To report the interim 5-year safety and effectiveness of abatacept in patients with juvenile idiopathic arthritis (JIA) in the PRINTO/PRCSG registry. METHODS: The Abatacept JIA Registry (NCT01357668) is an ongoing observational study of children with JIA receiving abatacept; enrolment started in January 2013. Clinical sites enrolled patients with JIA starting or currently receiving abatacept. Eligible patients were assessed for safety (primary end point) and effectiveness over 10 years. Effectiveness was measured by clinical 10-joint Juvenile Arthritis Disease Activity Score (cJADAS10) in patients with JIA over 5 years. As-observed analysis is presented according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. RESULTS: As of 31 March 2020, 587 patients were enrolled; 569 are included in this analysis (including 134 new users) with 1214.6 patient-years of safety data available. Over 5 years, the incidence rate (IR) per 100 patient-years of follow-up of serious adverse events was 5.52 (95% confidence interval [CI]: 4.27, 7.01) and of events of special interest was 3.62 (95% CI: 2.63, 4.86), with 18 serious infections (IR 1.48 [95% CI: 0.88, 2.34]). As early as month 3, 55.9% of patients achieved cJADAS10 low disease activity and inactive disease (20.3%, 72/354 and 35.6%, 126/354, respectively), sustained over 5 years. Disease activity measures improved over 5 years across JIA categories. CONCLUSION: Abatacept was well tolerated in patients with JIA, with no new safety signals identified and with well-controlled disease activity, including some patients achieving inactive disease or remission. TRIAL REGISTRATION: Clinicaltrials.gov, NCT01357668.

Childhood mixed connective tissue disease at disease onset: Evidence from a systematic review.

OBJECTIVE: Childhood Mixed Connective Tissue Disease (cMCTD) is the rarest pediatric connective tissue disease that includes features of systemic lupus erythematosus, polymyositis/dermatomyositis, juvenile idiopathic arthritis, and systemic sclerosis, identified by Sharp in 1972 and whose diagnosis remains challenging. This systematic review aims to identify clinical features at the onset of cMCTD and manifestations not currently included into the available diagnostic criteria. METHODS: A systematic literature review was performed in accordance with PRISMA guidelines 2020 using bibliographic databases: MEDLINE via PubMed and EMBASE. ELIGIBILITY CRITERIA: patients diagnosed with MCTD with onset before 18 years. STUDIES INCLUDED: registries, retrospective and prospective cohort studies, case series and reports with analysis of data on signs and symptoms of presentation. RESULTS: 39 articles were included (215 subjects, 82.5% female), mean age of 141 months (± 41 months DS, range 2.5-204). The most used criteria for the diagnosis of MCTD were the Kasukawa criteria (54.5%). The clinical manifestations described at onset were Raynaud's phenomenon (69.7%), arthritis (60.9%), muscular involvement (53.5%), dermatological signs (39.5%), swollen fingers or hands (29.3%), arthralgias (25.6%), fever (22.3%), lung involvement (14.4%), sclerodactily (13.5%), lymphadenopathy (10.7%) serositis (10.2%), esophageal involvement (6.9%), nervous system involvement (6.9%), xeroftalmia (3.7%), xerostomia (3.7%), hepatosplenomegaly (2.8%), cardiac involvement (2.8%), hepatitis (2.3%), parotiditis (2.3%), Hashimoto's thyroiditis (0.9%), ocular involvement (0.9%). CONCLUSIONS: The data from this systematic review suggest great heterogeneity of the clinical presentation of cMCTD for which there are no validated diagnostic criteria that may suggest a new diagnostic approach to allow earlier or more accurate diagnosis in the future.

Childhood Chronic Idiopathic Uveitis in a Multicentre International Cohort.

IMPORTANCE: Idiopathic uveitis makes up around 50% of non-infectious uveitis but the clinical characteristics in children are poorly understood. OBJECTIVE: To report the demographic, clinical characteristics, and outcomes of children with idiopathic non-infectious uveitis (iNIU) in a multicentric retrospective study. RESULTS: There were 126 (61 female) children with iNIU. The median age at diagnosis was 9.3 years (3-16 years) . Uveitis was bilateral in 106 patients and anterior in 68.At onset,impaired visual acuity and blindness in the worse eye were reported, in 24.4% and 15.1% patients but at 3 years of follow-up, there was a significant improvement in visual acuity (mean 0.11 SD ±0.50 vs 0.42 SD ± 0.59 p < .001). CONCLUSIONS AND RELEVANCE: There is a high rate of visual impairment at presentation in children with idiopathic uveitis. The majority of patients have a significant improvement in vision, but 1 in 6 had impaired vision or blindness in their worse eye at 3 years.

This is a large retrospective study of children with chronic idiopathic uveitis,There is a high rate of visual impairment at presentation in children with idiopathic uveitis. Although visual acuity improves during follow-up, one in six still had impaired vision or blindness in their worse eye at 3 years.At 3 years, more than half of patients were on immunosuppression and one-third were on a biologic agent.

Revising the value of Antistreptolysin O titre in childhood and its interpretation in the diagnostic approach of rheumatic diseases.

The burden of group A streptococcus (GAS) infection and its rheumatic sequelae remains dramatically high, especially in low-income countries. Recently, an increased number of Acute Rheumatic Fever (ARF) cases was documented in many regions of Italy. The diagnosis of rheumatic sequelae relies on clinical signs and on the evaluation of the Antistreptolysin O titre (ASO), whose variations are globally reported. To re-examine the standard reference value of ASO titre, by measuring either its upper limit of normal (ULN) in a population of healthy children (HC) or comparing these values with streptococcal antibodies registered in a cohort of patients affected by the rheumatic sequelae of GAS infection. We performed a multicenter retrospective study. We enrolled 125 HC, aged 2-17 years, and a total of 181 patients affected by ARF, acute streptococcal pharyngitis, post-streptococcal arthritis, Henoch-Schönlein purpura and erythema nodosum, divided into four groups. The levels of ASO and anti-deoxyribonuclease B (anti-DNase B) titres were analyzed and compared among the various groups. Moreover, the 80th percentile value was calculated and established as the ULN for ASO titre in HC group. The ULN for ASO titre in overall HC group was 515 IU/mL, resulting in higher than used in the routine investigation. The ASO titre was significantly higher in patients with rheumatic sequelae compared with HC group, with a peak in the age between 5 and 15 years.    Conclusion: Our study established a new ULN normal value of streptococcal serology in a childhood and adolescent population of Italy, suggesting the need to extend this revaluation to the critical areas, in order to avoid underestimating ARF diagnosis. The correct interpretation of ASO and anti-DNase B values in the context of rheumatic diseases has been discussed. What is Known: • The global burden of disease caused by group A streptococcus is not known and remains an important cause of morbidity and mortality. Acute rheumatic fever continues to be a serious worldwide public health problem and a recent recurrence of group A streptococcus infection cases is observed. • The streptococcal sequelae requires evidence of preceding streptococcal infection, commonly elevated streptococcal antibody titre, but the upper limit for these titres varies considerably based on age group, region, and origin. What is New: • This study provides population-specific values for streptococcal antibody titres in Italy. • Interpret the results of group A streptococcal antibody tests within the clinical context.

Early anakinra treatment improves cardiac outcome of multisystem inflammatory syndrome in children, regardless of disease severity.

OBJECTIVE: The main aim of this study was to define the best treatment option for multisystem inflammatory syndrome in children (MIS-C) and to analyse the role of anakinra. METHODS: This is a multicentre retrospective cohort study. Patients were treated according to the attending physician's decision. The patients were divided into four groups on the basis of the first treatment at time of admittance: (i) IVIG, (ii) IVIG and methylprednisolone (≤2 mg/kg/day), (iii) IVIG with high-dose methylprednisolone (>2 mg/kg/day) and (iv) anakinra with or without IVIG and/or methylprednisolone. Primary outcomes were defined as the presence of at least one of the following features: death, the failure of initial treatment, meaning the need for additional treatment for clinical worsening and cardiac involvement at the end of follow-up. RESULTS: Two hundred thirty-nine patients were recruited. At univariate analysis, persistent heart involvement at discharge was more frequent in those not receiving anakinra as initial treatment (3/21 vs 66/189; P = 0.047). After comparisons between the four treatment regimens, adjusting for the propensity score, we observed that early treatment with anakinra was associated with a lower probability of developing persistent heart disease at the end of follow-up (odds ratio: 0.6; 95% CI: 0.4-1.0). CONCLUSION: We report that early treatment with anakinra is safe and very effective in patients with severe MIS-C. In addition, our study suggests that early treatment with anakinra is the most favourable option for patients with a higher risk of developing a severe disease outcome.

Clinical features, treatment and outcomes of Italian children with enthesitis-related arthritis and juvenile psoriatic arthritis: a cross-sectional cohort study.

OBJECTIVES: Limited information is available on the clinical features, treatment modalities and outcomes of the juvenile idiopathic arthritis (JIA) categories of enthesitis-related arthritis (ERA) and juvenile psoriatic arthritis (JPsA). This study was aimed to describe the characteristics of Italian children with ERA and JPsA and to compare them with those of patients with the other categories of JIA. METHODS: Patients were part of a multinational sample included in a study aimed to investigate the prevalence of disease categories, treatment approaches, and disease status in patients from across different geographical areas (EPOCA Study). All patients underwent a retrospective assessment, based on the review of clinical chart, and a cross-sectional evaluation, which included assessment of physician- and parent-reported outcomes and laboratory tests, and recording of ongoing therapies. RESULTS: Of the 9081 children with JIA enrolled in the EPOCA Study, 1300 were recruited at 18 paediatric rheumatology centres in Italy. 45 (3.5%) had ERA and 49 (3.8%) had JPsA. Several remarkable differences in demographic features and frequency of articular and extra-articular manifestations, disease damage, impairment in physical function and health-related quality of life, school-related problems, comorbidities, and ongoing treatments were observed between ERA and JPsA and the other JIA categories. CONCLUSIONS: We described the characteristics of Italian children with ERA and JPsA and highlighted their peculiarities and their differences from the other JIA subsets. These data provide useful insights for future revisions of JIA classification and a benchmarking against which the features from other cohorts may be compared.