Therapeutic hypothermia for the management of hypoxic-ischemic encephalopathy in asphyxiated newborns: Clinical, electrographic and radiologic features of newborns treated at Instituto Materno Perinatal / Therapeutic hypothermia for the management of hypoxic-ischemic encephalopathy in asphyxiated newborns: Clinical, electrographic and radiological features of newborns treated at Instituto Materno Perinatal

La encefalopatía hipóxico-isquémica (EHI) es el síndrome neurológico causado por la asfixia perinatal. La hipotermia terapéutica (HT) ha demostrado reducir la mortalidad y morbilidad asociadas a EHI. Se realizó un estudio descriptivo retrospectivo con 30 recién nacidos con EHI moderada y severa que recibieron HT en la Unidad de Cuidados Intensivos del Instituto Materno Perinatal desde setiembre de 2017 a noviembre de 2020. Nueve de los casos fueron severos (30 %). El tiempo promedio de ingreso a HT fue 3.4 horas de vida. No se registraron efectos adversos importantes atribuibles a HT. Todos los pacientes severos tuvieron crisis epilépticas, ecografías cerebrales de ingreso y resonancias con anormalidades. La mortalidad fue de 20.0 %, aunque fue significativamente menor en el grupo con EHI moderada. Se identificaron las características de presentación clínica, electrográfica y radiológica de los neonatos con EHI que recibieron hipotermia terapéutica, la cual se muestra como un procedimiento seguro y efectivo.

Hipotermia terapéutica para tratamiento de encefalopatía hipóxico-isquémica del recién nacido asfixiado: Características clínicas, radiológicas y electrográficas de los neonatos atendidos en el Instituto Nacional Materno Perinatal

La encefalopatía hipóxico-isquémica (EHI) es el síndrome neurológico causado por la asfixia perinatal. La hipotermia terapéutica (HT) ha demostrado reducir la mortalidad y morbilidad asociadas a EHI. Se realizó un estudio descriptivo retrospectivo con 30 recién nacidos con EHI moderada y severa que recibieron HT en la Unidad de Cuidados Intensivos del Instituto Materno Perinatal desde setiembre de 2017 a noviembre de 2020. Nueve de los casos fueron severos (30 %). El tiempo promedio de ingreso a HT fue 3.4 horas de vida. No se registraron efectos adversos importantes atribuibles a HT. Todos los pacientes severos tuvieron crisis epilépticas, ecografías cerebrales de ingreso y resonancias con anormalidades. La mortalidad fue de 20.0 %, aunque fue significativamente menor en el grupo con EHI moderada. Se identificaron las características de presentación clínica, electrográfica y radiológica de los neonatos con EHI que recibieron hipotermia terapéutica, la cual se muestra como un procedimiento seguro y efectivo.

Hypoxic-ischemic encephalopathy (HIE) is the neurological syndrome caused by perinatal asphyxia. Therapeutic hypothermia (TH) has been shown to reduce HIE-associated morbidity and mortality. A descriptive and retrospective study with 30 newborns with moderate and severe HIE who underwent TH in the Intensive Care Unit (ICU) of Instituto Materno Perinatal, from September 2017 until November 2020. Nine patients were severely affected (30%). The average tome for being admitted in the ICU was at 3.4 hours of life. No important adverse effects attributable to TH were observed. All severely affected patients experienced epileptic crises, and abnormal cerebral ultrasonography and magnetic resonance imaging studies on admission. Mortality was 20.0%, but it was significantly lower in the group with moderate HIE. Clinical, electrographic, and radiological characteristics of neonates with HIE who underwent therapeutic hypothermia were identified. This procedure has been shown to be safe and effective.

Medication Optimization Using Pharmacogenomic Testing in a Complex Mental Health Population Prescribed Psychiatric Polypharmacy.

The use of polypharmacy has become significantly more common over the past two decades, increasing the risk of drug-drug interactions and adverse drug reactions. Pharmacogenomic (PGx) assays have the purported benefit of being able to predict an individual's response to a specific medication based on genetic markers, which may facilitate the development of optimized medication regimens for patients prescribed polypharmacy. This 12-week pilot study examined the impact of the PGx results on the clinical management of Veterans who were prescribed psychiatric polypharmacy. Psychiatric medication providers were given access to the PGx assay results, including notification of drug-drug-gene interactions computed from an algorithm decision tool, to assist with medication management decisions. Veteran outpatients (N = 53) prescribed polypharmacy (mean = 13.15 medications) were enrolled into the study. In 92.4% of cases, providers changed medications at baseline, with 83% of providers indicating that they changed their original medication plan based on the PGx results. Clinical improvement over the 12-week treatment phase was seen in depression (F(1.63, 45) = 5.45, P = .01, η2  = .11) and mental health quality of life (F(2.00, 45) = 4.16, P < .05, η2  = .16). Adverse drug effects were unchanged or improved over time. Rates of polypharmacy remained unchanged. The results suggest that medication changes based on the PGx assay may be beneficial in a complex patient population prescribed polypharmacy.

Síndrome de Pfeiffer tipo 2: diagnóstico prenatal. Reporte de caso y revisión de la literatura / Pfeiffer Syndrome Type 2: Prenatal diagnosis. Case report and literature review

Pfeiffer syndrome is an autosomic dominant disorder characterized by craniosynostosis, midface hypoplasia and syndactyly of the hands and feet. Three different phenotypes have been described, where type 2 is the most severe and the one amenable of prenatal diagnosis. We present the first clinical case reported at Instituto Nacional Materno Perinatal, Lima, Peru, of a fetus with suspicious ultrasound prenatal findings of this syndrome including cloverleaf-shaped skull, severe ventriculomegaly, frontal bossing, ocular proptosis and overlapped fingers, who was born by cesarean section and died at day eight due to progressive respiratory distress.

El síndrome de Pfeiffer es una enfermedad rara de tipo autosómica dominante caracterizada por craneosinostosis bicoronal, hipoplasia medio facial y sindactilia de manos y pies. Se ha descrito 3 fenotipos, siendo el tipo 2 el más severo y que generalmente se diagnostica prenatalmente. Presentamos el primer caso descrito en el Instituto Nacional Materno Perinatal de Lima, Perú, de un feto con hallazgos ultrasonográficos sospechosos de este síndrome, como el cráneo en forma de trébol, ventriculomegalia severa, frente abombada, ojos protruidos y dedos superpuestos, que nació por cesárea y falleció a los 8 días de edad por distrés respiratorio progresivo.

S100A12 and S100A8/9 proteins are biomarkers of articular disease activity in Blau syndrome.

OBJECTIVE: To identify biomarkers of articular and ocular disease activity in patients with Blau syndrome (BS). METHODS: Multiplex plasma protein arrays were performed in five BS patients and eight normal healthy volunteers (NHVs). Plasma S100A12 and S100A8/9 were subsequently measured by ELISA at baseline and 1-year follow-up in all patients from a prospective multicentre cohort study. CRP was measured using Meso Scale Discovery immunoassay. Active joint counts, standardization uveitis nomenclature for anterior uveitis cells and vitreous haze by Nussenblatt scale were the clinical parameters. RESULTS: Multiplex Luminex arrays identified S100A12 as the most significantly elevated protein in five selected BS vs eight NHVs and this was confirmed by ELISA on additional samples from the same five BS patients. In the patient cohort, S100A12 (n = 39) and S100A8/9 (n = 33) were significantly higher compared with NHVs (n = 44 for S100A12, n = 40 for S100A8/9) (P = 0.0000004 and P = 0.0003, respectively). Positive correlations between active joint counts and S100 levels were significant for S100A12 (P = 0.0008) and S100A8/9 (P = 0.015). CRP levels did not correlate with active joint count. Subgroup analysis showed significant association of S100 proteins with active arthritis (S100A12 P = 0.01, S100A8/9 P = 0.008). Active uveitis was not associated with increased S100 levels. CONCLUSION: S100 proteins are biomarkers of articular disease activity in BS and potential outcome measures in future clinical trials. As secreted neutrophil and macrophage products, S100 proteins may reflect the burden of granulomatous tissue in BS.

Development and Initial Validation of the Macrophage Activation Syndrome/Primary Hemophagocytic Lymphohistiocytosis Score, a Diagnostic Tool that Differentiates Primary Hemophagocytic Lymphohistiocytosis from Macrophage Activation Syndrome.

OBJECTIVE: To develop and validate a diagnostic score that assists in discriminating primary hemophagocytic lymphohistiocytosis (pHLH) from macrophage activation syndrome (MAS) related to systemic juvenile idiopathic arthritis. STUDY DESIGN: The clinical, laboratory, and histopathologic features of 362 patients with MAS and 258 patients with pHLH were collected in a multinational collaborative study. Eighty percent of the population was assessed to develop the score and the remaining 20% constituted the validation sample. Variables that entered the best fitted model of logistic regression were assigned a score, based on their statistical weight. The MAS/HLH (MH) score was made up with the individual scores of selected variables. The cutoff in the MH score that discriminated pHLH from MAS best was calculated by means of receiver operating characteristic curve analysis. Score performance was examined in both developmental and validation samples. RESULTS: Six variables composed the MH score: age at onset, neutrophil count, fibrinogen, splenomegaly, platelet count, and hemoglobin. The MH score ranged from 0 to 123, and its median value was 97 (1st-3rd quartile 75-123) and 12 (1st-3rd quartile 11-34) in pHLH and MAS, respectively. The probability of a diagnosis of pHLH ranged from <1% for a score of <11 to >99% for a score of ≥123. A cutoff value of ≥60 revealed the best performance in discriminating pHLH from MAS. CONCLUSION: The MH score is a powerful tool that may aid practitioners to identify patients who are more likely to have pHLH and, thus, could be prioritized for functional and genetic testing.

Miastenia gravis de tipo bulbar en niños: un caso de difícil diagnóstico / Bulbar Myasthenia Gravis in children: a case of difficult diagnosis

La miastenia gravis (MG) es un trastorno autoinmune caracterizado por debilidad y fatigabilidad de los músculos esqueléticos debida a la disfunción de la unión neuromuscular. Se presenta el caso de una adolescente de 11 años de edad, con diagnóstico de miastenia gravis de tipo bulbar. La paciente presentó dos crisis de MG previamente diagnosticadas de manera equivocada como crisis asmáticas. Recibió tratamiento con inmunoglobulina humana, corticoides, piridostigmina y timectomía. Se discute la evolución clínica y riesgos atribuibles a situaciones sociales que pueden retrasar el diagnóstico y su manejo efectivo.

Myasthenia gravis (MG) is an autoimmune disorder characterized by weakness and fatigability of the skeletal muscles due to dysfunction of the neuromuscular junction. We report the case of an 11-year-old girl diagnosed with bulbar myasthenia gravis. The patient had two previous crises of myasthenia gravis erroneously diagnosed as asthma attacks. She received treatment with human immunoglobulin, corticosteroids, pyridostigmine and thymectomy. We discuss the clinical course and the risks attributable to social situations that can delay the diagnosis and its effective management.

Efficacy and safety of canakinumab in cryopyrin-associated periodic syndromes: results from a Spanish cohort.

OBJECTIVES: Cryopyrin-associated periodic syndromes (CAPS) are dominantly-inherited autoinflammatory diseases. The uncontrolled IL-1ß overproduction observed in these patients is the rational basis to treat them with anti-IL-1 drugs. The objective of this study was to evaluate the efficacy and safety of treatment with the long-lasting fully humanised anti-IL-1ß monoclonal antibody canakinumab in a Spanish cohort of patients with CAPS. METHODS: Clinical and laboratory data of CAPS patients carrying a heterozygous germline NLRP3 mutation were obtained. The initial treatment scheme with canakinumab was 150 mg/8 weeks administered subcutaneously in adult patients and 2 mg/kg/8 weeks in paediatric patients. RESULTS: Eight unrelated patients were enrolled. Canakinumab was the first anti-IL-1 drug used in three of them; five were already receiving anakinra. The clinical response to the initial canakinumab scheme was positive in all patients, and was quickly observed in the first 24-72 hours. Four required increasing the frequency and/or dose of canakinumab. A limited or no efficacy in those symptoms related to consequence of the deforming arthropathy and neurosensorial deafness was observed. The adverse side effects were restricted to infectious complications in a small percentage of patients. The treatment was well tolerated by all patients, with no reactions at drug site injections. CONCLUSIONS: Canakinumab caused fast and sustained remissions in most clinical and biochemical manifestations in all enrolled patients, with a limited efficacy in the structural lesions. Dose adjustments seem to be necessary for children and/or for patients with the most severe CAPS phenotypes. Treatment was well tolerated with a low incidence of adverse effects.

Clinical management algorithm of uveitis associated with juvenile idiopathic arthritis: interdisciplinary panel consensus.

Uveitis associated with juvenile idiopathic arthritis (JIA) typically involves the anterior chamber segment, follows an indolent chronic course, and presents a high rate of uveitic complications and a worse outcome as compared to other aetiologies of uveitis. Disease assessment, treatment, and outcome measures have not been standardized. Collaboration between pediatric rheumatologists and ophthalmologists is critical for effective management and prevention of morbidity, impaired vision, and irreparable visual loss. Although the Standardization of Uveitis Nomenclature Working Group recommendations have been a great advance to help clinicians to improve consistency in grading and reporting data, difficulties arise at the time of deciding the best treatment approach in the individual patient in routine daily practice. For this reason, recommendations for a systematized control and treatment strategies according to clinical characteristics and disease severity in children with JIA-related uveitis were developed by a panel of experts with special interest in uveitis associated with JIA. A clinical management algorithm organized in a stepwise regimen is here presented.

Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes.

OBJECTIVE: To report baseline articular, functional and ocular findings of the first international prospective cohort study of Blau syndrome (BS). METHODS: Three-year, multicentre, observational study on articular, functional (HAQ, Childhood HAQ and VAS global and pain), ophthalmological, therapeutic and radiological data in BS patients. RESULTS: Baseline data on the first 31 recruited patients (12 females and 19 males) from 18 centres in 11 countries are presented. Of the 31 patients, 11 carried the p.R334W NOD2 mutation, 9 the p.R334Q and 11 various other NOD2 missense mutations; 20 patients were sporadic and 11 from five BS pedigrees. Median disease duration was 12.8 years (1.1-57). Arthritis, documented in all but one patient, was oligoarticular in 7, polyarticular in 23. The median active joint count was 21. Functional capacity was normal in 41%, mildly impaired in 31% and moderate-severe in 28% of patients. The most frequently involved joints at presentation were wrists, ankles, knees and PIPs. On radiographs, a symmetrical non-erosive arthropathy was shown. Previously unknown dysplastic bony changes were found in two-thirds of patients. Ocular disease was documented in 25 of 31 patients, with vitreous inflammation in 64% and moderate-severe visual loss in 33%. Expanded manifestations (visceral, vascular) beyond the classic clinical triad were seen in 52%. CONCLUSION: BS is associated with severe ocular and articular morbidity. Visceral involvement is common and may be life-threatening. Bone dysplastic changes may show diagnostic value and suggest a previously unknown role of NOD2 in bone morphogenesis. BS is resistant to current drugs, suggesting the need for novel targeted therapies.

Clinical features, treatment, and outcome of macrophage activation syndrome complicating systemic juvenile idiopathic arthritis: a multinational, multicenter study of 362 patients.

OBJECTIVE: To describe the clinical, laboratory, and histopathologic features, current treatment, and outcome of patients with macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (JIA). METHODS: In this multinational, multicenter study, pediatric rheumatologists and hemato-oncologists entered patient data collected retrospectively into a web-based database. RESULTS: A total of 362 patients, 22% of whom had MAS at the onset of systemic JIA, were included in the study by 95 investigators from 33 countries. The most frequent clinical manifestations were fever (96%), hepatomegaly (70%), and splenomegaly (58%). Central nervous system dysfunction and hemorrhages were recorded in 35% and 20% of the patients, respectively. Platelet count and liver transaminase, ferritin, lactate dehydrogenase, triglyceride, and d-dimer levels were the sole laboratory biomarkers showing a percentage change of >50% between the pre-MAS visit and MAS onset. Evidence of macrophage hemophagocytosis was found in 60% of the patients who underwent bone marrow aspiration. MAS occurred most frequently in the setting of active underlying disease, in the absence of a specific trigger. Nearly all patients were given corticosteroids, and 61% received cyclosporine. Biologic medications and etoposide were given to 15% and 12% of the patients, respectively. Approximately one-third of the patients required admission to the intensive care unit (ICU), and the mortality rate was 8%. CONCLUSION: This study provides information on the clinical spectrum and current management of systemic JIA-associated MAS through the analysis of a very large patient sample. MAS remains a serious condition, as a sizeable proportion of patients required admission to the ICU or died.

Adalimumab therapy for refractory childhood uveitis.

PURPOSE: To report the results of adalimumab therapy in a cohort of children with refractory noninfectious uveitis. METHODS: The medical records of patients diagnosed with uveitis and treated with biweekly adalimumab injections for a period of at least 3 months at the University Hospital of La Paz from 2007-2012 were retrospectively reviewed. Improvement in inflammatory activity was graded according to grading schema of the Standardization of Uveitis Nomenclature Working Group. RESULTS: A total of 15 patients participated in the study (12 girls; mean patient age, 12 years). Diagnoses included juvenile idiopathic arthritis in 10 patients, idiopathic uveitis in 4, and familial juvenile systemic granulomatosis or Blau syndrome in 1. Mean follow-up was 32 months (median, 36; range, 15-58 months). Improvement in inflammatory activity was initially observed in 12 (86%) of 14 children, with a mean time to achieve response of 6 weeks (median, 4; range, 1-18). Treatment was effective in 9 patients (60%), mildly effective in 2 (13%), ineffective in 2 (13%), and resulted in worsening in 2 (13%). In the juvenile idiopathic arthritis patients, response was effective in 6 cases (60%), mildly effective in 2 (20%), and ineffective in 2 (20%). Adalimumab therapy was discontinued in 4 patients. CONCLUSIONS: Adalimumab was effective in most patients in the initial control of acute inflammatory activity in children with refractory uveitis, although therapy appears to become less effective in the long term.

High incidence of NLRP3 somatic mosaicism in patients with chronic infantile neurologic, cutaneous, articular syndrome: results of an International Multicenter Collaborative Study.

OBJECTIVE: Chronic infantile neurologic, cutaneous, articular (CINCA) syndrome, also known as neonatal-onset multisystem inflammatory disease (NOMID), is a dominantly inherited systemic autoinflammatory disease. Although heterozygous germline gain-of-function NLRP3 mutations are a known cause of this disease, conventional genetic analyses fail to detect disease-causing mutations in ∼40% of patients. Since somatic NLRP3 mosaicism has been detected in several mutation-negative NOMID/CINCA syndrome patients, we undertook this study to determine the precise contribution of somatic NLRP3 mosaicism to the etiology of NOMID/CINCA syndrome. METHODS: An international case-control study was performed to detect somatic NLRP3 mosaicism in NOMID/CINCA syndrome patients who had shown no mutation during conventional sequencing. Subcloning and sequencing of NLRP3 was performed in these mutation-negative NOMID/CINCA syndrome patients and their healthy relatives. Clinical features were analyzed to identify potential genotype-phenotype associations. RESULTS: Somatic NLRP3 mosaicism was identified in 18 of the 26 patients (69.2%). Estimates of the level of mosaicism ranged from 4.2% to 35.8% (mean ± SD 12.1 ± 7.9%). Mosaicism was not detected in any of the 19 healthy relatives (18 of 26 patients versus 0 of 19 relatives; P < 0.0001). In vitro functional assays indicated that the detected somatic NLRP3 mutations had disease-causing functional effects. No differences in NLRP3 mosaicism were detected between different cell lineages. Among nondescript clinical features, a lower incidence of mental retardation was noted in patients with somatic mosaicism. Genotype-matched comparison confirmed that patients with somatic NLRP3 mosaicism presented with milder neurologic symptoms. CONCLUSION: Somatic NLRP3 mutations were identified in 69.2% of patients with mutation-negative NOMID/CINCA syndrome. This indicates that somatic NLRP3 mosaicism is a major cause of NOMID/CINCA syndrome.

NOD2-associated pediatric granulomatous arthritis, an expanding phenotype: study of an international registry and a national cohort in Spain.

OBJECTIVE: To study the phenotype characteristics of the largest to date cohort of patients with pediatric granulomatous arthritis (PGA) and documented mutations in the NOD2 gene. METHODS: We analyzed merged data from 2 prospective cohorts of PGA patients, the International PGA Registry and a Spanish cohort. A systematic review of the medical records of interest was performed to identify phenotype characteristics. RESULTS: Forty-five patients with PGA (23 sporadic cases and 22 from familial pedigrees) and documented NOD2 mutations were identified and formed the basis of the study. Of these 45 patients, 18 had the R334W-encoding mutation, 18 had R334Q, 4 had E383K, 3 had R587C, 1 had C495Y, and 1 had W490L. The majority of patients manifested the typical triad of dermatitis, uveitis, and arthritis. In contrast, in 13 patients, the following "atypical" manifestations were noted: fever, sialadenitis, lymphadenopathy, erythema nodosum, leukocytoclastic vasculitis, transient neuropathy, granulomatous glomerular and interstitial nephritis, interstitial lung disease, arterial hypertension, hypertrophic cardiomyopathy, pericarditis, pulmonary embolism, hepatic granulomatous infiltration, splenic involvement, and chronic renal failure. In addition, 4 individuals who were asymptomatic carriers of a disease-causing mutation were documented. CONCLUSION: NOD2-associated PGA can be a multisystem disorder with significant visceral involvement. Treating physicians should be aware of the systemic nature of this condition, since some of these manifestations may entail long-term morbidity.

NOD2 gene-associated pediatric granulomatous arthritis: clinical diversity, novel and recurrent mutations, and evidence of clinical improvement with interleukin-1 blockade in a Spanish cohort.

OBJECTIVE: Blau syndrome and early-onset sarcoidosis are NOD2 gene-associated chronic autoinflammatory diseases characterized by skin rash, arthritis, and/or eye involvement, with noncaseating granulomata as their pathologic hallmark. This study was undertaken to describe the expanded clinical phenotype, treatment outcomes, and NOD2 gene mutation analysis in a Spanish cohort with pediatric granulomatous arthritis, a chronic disease resembling Blau syndrome/early-onset sarcoidosis. METHODS: Clinical, laboratory, and treatment data on the 12 patients in the cohort were obtained through direct interviews. NOD2 gene analysis was performed in a central laboratory, by bidirectional sequencing. Cytokine levels were measured using the human Flex-Set cytokine bead array. RESULTS: The classic Blau syndrome/early-onset sarcoidosis triad of skin rash, arthritis, and recurrent uveitis was identified in 5 patients (41.7%), whereas 7 patients (58.3%) presented with fewer than 3 of the classic features. Novel atypical manifestations such as persistent fever and myocardiopathy were also observed. NOD2 analysis revealed 1 heterozygous mutation in each patient, and familial studies confirmed its full penetrance. Of the 12 cases, 58.3% were sporadic, due to de novo mutations. Four different missense mutations on exon 4 were detected. Two of them (R334W and R334Q) were recurrent mutations and were found in 77.8% of the Spanish families, whereas the other 2 (C495Y and R587C) were novel. In the patient who received anakinra treatment, all clinical inflammatory symptoms improved and plasma cytokine levels normalized. CONCLUSION: These findings indicate that the expanding clinical heterogeneity of the disease (that is, the presentation of incomplete forms of the classic triad and atypical manifestations) and the high prevalence of sporadic cases should alert clinicians to the possible genetic basis of the condition and support the inclusion of DNA analysis as a diagnostic test. The positive response to anakinra observed in 1 patient suggests a new potential therapeutic approach that merits further investigation, and suggests that the pathogenesis of pediatric granulomatous arthritis may involve interleukin-1-mediated events.

Evaluation of revised International League of Associations for Rheumatology classification criteria for juvenile idiopathic arthritis in Spanish children (Edmonton 2001).

OBJECTIVE: To evaluate the revised (Edmonton 2001) International League of Associations for Rheumatology (ILAR) classification criteria for Juvenile Idiopathic Arthritis (JIA) in a cohort of Spanish children. METHODS: One hundred twenty-five patients with chronic arthritis categorized according to traditional criteria and to the first revision of ILAR JIA criteria (Durban 1997) were reclassified according to the second JIA criteria revision (Edmonton 2001). RESULTS: Edmonton criteria allocated 92% of the patients classified by traditional criteria in their corresponding ILAR categories. Most patients with systemic (94%), pauciarticular (91%) and polyarticular (88%) juvenile chronic arthritis as well as those with juvenile spondyloarthropathy (94%) were reclassified in the corresponding ILAR categories. Two children with probable psoriatic arthritis (PsA) were reclassified in the rheumatoid factor-negative (RF-) polyarthritis category, whereas only one of 2 children with definite PsA could be allocated to the ILAR PsA class. Ten patients (8%) constituted the undifferentiated arthritis group, 8 because of psoriasis in a first-degree relative, one because of the presence of RF in a girl with oligoarthritis, and another because of psoriasis in a boy who was HLA-B27-positive. In comparison with the Durban JIA criteria the Edmonton revision decreased the number of patients whose arthritis fulfilled criteria in no category or in 2 or more categories (from 19 to 10), and delineated better the population included in the RF- polyarthritis category. CONCLUSION: The Edmonton criteria made the ILAR classification more transparent and easy to apply. Family history of psoriasis was responsible for most allocations to the undifferentiated arthritis category (8/10).