Outbreak of Streptococcus pyogenes infection in healthcare workers in a paediatric intensive care unit: transmission from a single patient.

A 15-h stay in a paediatric intensive care unit by a girl with generalized dermal lesions superinfected with Streptococcus pyogenes led to four streptococcal infections in healthcare workers. Phenotypic and molecular analyses of the strains revealed that four isolates, characterized as emm87/ST62/T28, were identical to the isolate obtained from the index case. The occurrence of this outbreak, despite of the girl's brief hospital stay and appropriate patient management, highlights the high transmissibility of this pathogen.

Rotavirus genotypes in children in the Basque Country (North of Spain): rapid and intense emergence of the G12[P8] genotype.

Between July 2009 and June 2011, rotavirus was detected in 507 of 4597 episodes of acute gastroenteritis in children aged <3 years in Gipuzkoa (Basque Country, Spain), of which the G-type was determined in 458 (90·3%). During the annual seasonal epidemic of 2010-2011, the unusual G-type 12 was predominant, causing 65% (145/223) of cases of rotavirus gastroenteritis. All the G12 strains were clustered in lineage III and were preferentially associated with P-type 8. This epidemic was characterized by broad geographical distribution (rural and urban) and, over 7 months, affected both infants and children, the most frequently affected being children between 4 and 24 months. Of children with rotavirus G12, 16% required hospital admission, the admission rate in children aged <2 years being 20·7 cases/10 000 children. The sudden emergence and predominance of G12 rotaviruses documented in this winter outbreak suggest that they may soon become a major human rotavirus genotype.

Factors associated with cortisol levels and health in 5-6-year-old children.

OBJECTIVES: This study assesses the relationships between social context (family and inter-peer context), stress, and illness in 5-6-year-old children. METHODS: To this end, data were collected on spontaneous social interpeer behavior; families provided data on stress, anxiety, and parental acceptance-rejection; and the children's pediatricians provided data relative to their health. Data on stress-related hormones (cortisol) were collected using saliva samples. RESULTS: The results revealed that none of the variables examined were significantly related to illness development in the subjects in the sample group. Cortisol levels, however, were positively associated with a record of chronic or congenital illnesses, the manifestation of behaviors related to the search for leadership status in the group and the presence of stressful events in the family environment. CONCLUSIONS: Despite finding no relationship between children's level of adrenocortical activity and the contracting or contingent development of diseases, we did find that chronic/congenital diseases may constitute a source of early stress in childhood. Certain conditions of uncertainty in the social context (family and interpeer) also seem to constitute different sources of stress.

Improving anaphylaxis management in a pediatric emergency department.

BACKGROUND: The management of anaphylaxis in pediatric emergency units (PEU) is sometimes deficient in terms of diagnosis, treatment, and subsequent follow-up. The aims of this study were to assess the efficiency of an updated protocol to improve medical performance, and to describe the incidence of anaphylaxis and the safety of epinephrine use in a PEU in a tertiary hospital. METHODS: We performed a before-after comparative study with independent samples through review of the clinical histories of children aged <14 years old diagnosed with anaphylaxis in the PEU according to the criteria of the European Academy of Allergy and Clinical Immunology (EAACI). Two allergists and a pediatrician reviewed the discharge summaries codified according to the International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) as urticaria, acute urticaria, angioedema, angioneurotic edema, unspecified allergy, and anaphylactic shock. Patients were divided into two groups according to the date of implantation of the protocol (2008): group A (2006-2007; the period before the introduction of the protocol) and group B (2008-2009; after the introduction of the protocol). We evaluated the incidence of anaphylaxis, epinephrine administration, prescription of self-injecting epinephrine (SIE), other drugs administered, the percentage of admissions and length of stay in the pediatric emergency observation area (PEOA), referrals to the allergy department, and the safety of epinephrine use. RESULTS: During the 4 years of the study, 133,591 children were attended in the PEU, 1673 discharge summaries were reviewed, and 64 cases of anaphylaxis were identified. The incidence of anaphylaxis was 4.8 per 10,000 cases/year. After the introduction of the protocol, significant increases were observed in epinephrine administration (27% in group A and 57.6% in group B) (p = 0.012), in prescription of SIE (6.7% in group A and 54.5% in group B) (p = 0.005) and in the number of admissions to the PEOA (p = 0.003) and their duration (p = 0.005). Reductions were observed in the use of corticosteroid monotherapy (29% in group A, 3% in group B) (p = 0.005), and in patients discharged without follow-up instructions (69% in group A, 22% in group B) (p = 0.001). Thirty-three epinephrine doses were administered. Precordial palpitations were observed in one patient. CONCLUSION: The application of the anaphylaxis protocol substantially improved the physicians' skills to manage this emergency in the PEU. Epinephrine administration showed no significant adverse effects.

Incidence of hospitalization due to community-acquired rotavirus infection: a 12-year study (1996-2008).

The incidence of hospitalization for acute gastroenteritis (AGE) is a useful parameter to assess the utility of the new rotavirus vaccines in high-income countries. Children hospitalized for AGE were identified by searching hospital discharge data and the records of the microbiology laboratory of Hospital Donostia. Rotavirus antigen was investigated in 96.1% of the 1114 children aged 1 month to <5 years hospitalized for AGE in the study period. Nearly 40% were rotavirus positive (44.9% of the 798 children aged 1 month to <2 years), with G1[P8] being the predominant genotype. The mean annual incidence rate of hospitalization due to rotavirus AGE was 29.8 and 63.7 cases/10 000 inhabitants in the <5 and <2 years age groups, respectively, in 1996-1999, decreasing to 13.6 and 27.4 cases/10 000 inhabitants in <5 and <2 years age groups, respectively, in 2002-2005 (P<0.001). This decrease coincided with a significant increase in the consumption of oral rehydration solutions.

Invasive Streptococcus pneumoniae infections in children and older adults in the north of Spain before and after the introduction of the heptavalent pneumococcal conjugate vaccine.

In the last two decades, an increasing trend in the incidence of pneumococcal disease in Europe has been reported. We investigated the effect of the use of the heptavalent pneumococcal conjugate vaccine (PCV7) in an area of northern Spain, where all recorded cases of invasive pneumococcal diseases (IPD) were included (n = 450; 91 between 1996-2007 in children aged <5 years and 359 between 1998-2007 in adults aged >64 years). All isolates were serotyped. In children, the overall IPD incidence did not significantly decrease after the introduction, in late 2001, of PCV7. However, the incidence of PCV7 serotypes significantly decreased by 137.2% from 31.59 cases/100,000 population in 1996-2001 to 13.42 in 2002-2007 (95% confidence interval [CI] -27.2 to -342.4%), as did the overall rates of penicillin resistance (from 45.6 to 18.6%) and multiresistance (from 30.3 to 11%). In older adults, the overall IPD incidence showed a non-significant increase due to non-PCV7 serotypes, which seemed to continue a previous trend in our region.

[Forced spirometry in healthy preschool children]. / Espirometría forzada en preescolares sanos bajo las recomendaciones de la ATS/ERS: estudio CANDELA.

INTRODUCTION: Reference values for spirometry in healthy preschool children have not yet been obtained in accordance with American Thoracic Society (ATS) and the European Respiratory Society (ERS) guidelines. The objective was to establish reference values for spirometry in healthy preschoolers under the ATS/ERS 2007 statement. MATERIAL AND METHOD: Children of at least 2 and under 7 years of age were tested in 9 pediatric pulmonary function laboratories. The technicians were trained to apply a standardized protocol to perform spirometry. RESULTS: Valid spirometry results were obtained in 455 (81.54%) out of 558 children: 242 boys (53.2%) and 213 girls (46.8%). Ages were as follows: 31 at least 2 and under 3 years old; 96, at least 3 and under 4; 108, at least 4 and under 5; 122, at least 5 and under 6 years, and 98, at least 6 and under 7 years. Formulas were used to calculate the reference values for all the spirometry variables in preschoolers. CONCLUSIONS: Spirometry is feasible in the majority of preschool children under the new guidelines. The availability of the reference values presented is an important step, both for the care of preschoolers and for further research on pulmonary function.

[Recurrent wheezing in three year-olds: facts and opportunities]. / Sibilancias recurrentes en menores de tres años: evidencias y oportunidades.

The 3 year-old group of children has an increased incidence and prevalence of recurrent wheezing episodes. There are different subgroups, who give different inflammatory responses to different triggering agents, and subgroups that differ in aetiopathology and immunopathology. Current diagnostic methods (exhaled nitric oxide in multiple breaths, nitric oxide in exhaled air condensate, induced sputum, broncho-alveolar lavage and endo-bronchial biopsy), enable the inflammatory pattern to be identified and to give the most effective and safe treatment. The various therapeutic options for treatment are reviewed, such as inhaled glucocorticoids when the inflammatory phenotype is eosinophilic, and leukotriene receptor antagonists, when the inflammatory phenotype is predominantly neutrophilic. In accordance with the current recommendations, for the diagnosis as well as for the therapy initiated in children of this age, they must be regularly reviewed, so that if the benefit is not clear, the treatment must be stopped and an alternative diagnosis and treatment considered. The start of treatment should be determined depending on the intensity and frequency of the symptoms, with the aim of decreasing morbidity and increasing the quality of life of the patient.

[Genetic diagnostic criteria in cases of mental retardation and development of idiopathic origin]. / Criterios de diagnóstico genético en casos de retraso mental y del desarrollo de origen idiopático.

Different studies show that mental retardation affects 1-3% of the population, and in about 50 % of the cases the aetiology is unknown. The uncertainty on the aetiology, and recurrence, means that prevention of mental retardation can have serious, therapeutic, social, and even economic repercussions. The key is to obtain an accurate diagnosis, proving a clinical hypothesis by the accomplishment of the most suitable genetic tests. Due to the increasing development of the technology in the field of the genetics, and the availability of new tests, this article reviews the criteria established in the practice guidelines from different scientific societies (paediatric, neurological and genetic) with respect to their use in diagnosis and integrates them from the point of view of their use in mental retardation and developmental delay.

[Fractional exhaled nitric oxide: validation of a 6 second exhalation time with two different analysers]. / Fracción exhalada de óxido nítrico: validación de la medida con tiempo de espiración de 6 s con dos analizadores diferentes.

OBJECTIVE: To validate the measurement of fractional exhaled nitric oxide concentration (FE(NO)) using a 6-sec exhalation time in patients aged between 5 and 17 years with a stationary chemiluminescence analyser (NIOX, Aerocrine) and a portable electrochemical analyser (NIOX-MINO, Aerocrine). MATERIAL AND METHODS: FE(NO) was assessed in 60 patients randomised into two groups. In Group 1 (n = 30, NIOX analyser), three valid FE(NO) measurements were obtained for two exhalation times (10 sec and 6 sec); the mean of the three measurements was recorded. In Group 2 (n = 30, NIOX-MINO), a single valid measurement of FE(NO) was obtained for each exhalation time. We analysed age, gender, weight, height, diagnosis, treatment, FE(NO) and the number of attempts with both exhalation times in each analyser. Agreement between FE(NO) assessed using 10-sec and 6-sec exhalations was assessed by Bland-Altman analysis and Cohen's kappa. RESULTS: The mean (SD) age in Group 1 was 10.1 (3.07) years. The mean age in Group 2 was 10.43 (2.94) years. Bland-Altman analysis demonstrated good agreement between FE(NO) values obtained with both exhalation times and with both devices. Cohen's kappa, also demonstrated good agreement (NIOX, kappa = 1; NIOX-MINO, kappa = 0.93). CONCLUSIONS: A 6-sec exhalation time is valid for measuring FE(NO) with both analysers in children aged over 5 years.

[Spanish version of the TNO-AZL preschool children quality of life questionnaire (TAPQOL)]. / Versión española del TAPQOL: calidad de vida relacionada con la salud en niños de 3 meses a 5 años.

OBJECTIVES: To obtain a Spanish version of the TNO-AZL Preschool Children Quality of Life Questionnaire (TAPQOL) that would be both semantically and culturally equivalent to the original. MATERIAL AND METHODS: The TAPQOL questionnaire was designed to measure health-related quality of life in children aged 3 months to 5 years and contains 43 questions distributed in 12 subdimensions. The Spanish version was obtained by using the forward/back-translation method with expert, bilingual translators. Cognitive debriefing interviews were carried out with the parents of healthy children and with those of children with respiratory disease. RESULTS: During the adaptation phase, four items were modified after input from the authors of the original version to retain the meaning of the original. At the end of the adaptation process, 37 of the 43 items were classified as A, i.e. without difficulty in the adaptation. Four mothers and two fathers participated in the cognitive debriefing interviews. Four had secondary level education, and two had university level education. Their children were aged between 16 and 60 months. The average time taken to complete the questionnaire was 13.5 minutes. No comprehension problems regarding the questionnaire's content were found, and no items were modified after this phase of the study. The mothers of children with respiratory disease considered the questions related to their children's symptoms to be appropriate. CONCLUSIONS: The Spanish version of the TAPQOL has proven to be acceptable and culturally equivalent to the original version. Future studies should investigate the psychometric properties of this questionnaire and compare them with those of the original version.

[Spanish multidisciplinary consensus on the prevention of respiratory syncytial virus infection in children]. / Consenso multidisciplinar español sobre la profilaxis de la infección respiratoria pediátrica por virus respiratorio sincitialConsenso.

BACKGROUND: A certain degree of feasibility exists in Spanish clinical practice with respect to interventions performed to prevent paediatric respiratory infection by RSV, including hygienic measures and intramuscular immunoprophylaxis with palivizumab. This task involves different paediatric specialties that may have a different perception of the magnitude of the problem and different professional criteria regarding the most appropriate actions. OBJECTIVES: To develop Spanish multidisciplinary consensus on preventing infection by RSV with the participation of the paediatric scientific societies involved (SNS, SSPC, SSPP and SSHPO). METHODS: Delphi Consensus modified in two rounds was used. The study was conducted in four phases: 1) constitution of a multidisciplinary Scientific Committee at the recommendation of the scientific entities participating in the study, for bibliographic review and submission of the recommendations to discussion; 2) constitution of an Expert Panel with 77 speciality representatives; 3) postal survey organised in two rounds and intermediate processing of opinions and issuing of a report for the panellists, and 4) discussion of the results in a meeting of the Scientific Committee. RESULTS: Consensus was reached on 48 of the 57 preventive recommendations analysed. With respect to the 9 remaining issues, no consensus was reached, due to differences in professional opinion and the absence of established criteria among the majority of the experts. Only in 3 recommendations was the opinion of the experts associated with the speciality of origin. CONCLUSIONS: A list of anti-RSV prophylactic recommendations was submitted, rated in accordance with the degree of professional consensus on which they were based. These can be considered valid until such time as new scientific information emerges that warrants a review thereof.

[Agreement between two devices for measuring exhaled nitric oxide]. / Concordancia entre dos dispositivos de medida de óxido nítrico exhalado.

BACKGROUND: Measurement of fractional exhaled nitric oxide (FENO) is a non-invasive marker of eosinophilic airway inflammation that can be useful in asthma diagnosis and control, as well as in treatment monitoring. OBJECTIVE: We studied the correlation between two techniques for measuring FENO: the chemiluminescence-based analyzer (NIOX, Aerocrine, Sweden) and a new portable electrochemical sensor-based analyzer (NIOX-MINO, Aerocrine). MATERIAL AND METHODS: FENO was measured by the single breath on-line method. In all children, three consecutives measurements were obtained with NIOX, with a maximum of six attempts, and the arithmetic mean was calculated. Next, using NIOX-MINO, a single measurement was made successively in each of the children. The variables analyzed were sex, age, height, weight, diagnosis, treatment, NIOX-MINO value, mean of three values obtained with NIOX and the NO elimination rate (nL/min). For the statistical analysis, the Bland-Altman plot was used to compare the means and the differences between measurements of FENO from NIOX and NIOX-MINO. The agreement between the two analyzers was estimated by Cohen's Kappa statistic. RESULTS: Thirty children were included, 14 (46.67%) boys and 16 (53.33%) girls. The mean age was 11.3+/-3.09 years. All of the children successfully performed the measurements with two analyzers. The relationship between the means and the differences in the values obtained with NIOX-MINO and NIOX were statistically significant (p<0.005). In addition, Cohen's Kappa statistic (0.78) suggested a high degree of agreement between the results obtained with the two devices. CONCLUSIONS: The two analyzers, NIOX-MINO and NIOX, were not equivalent. There was good agreement between the FENO values measured with the two devices. Measurement of FENO with the portable electrochemical sensor-based analyzer (NIOX-MINO) is valid and feasible in children older than 5 years.

[Current prevalence of asthma in schoolchildren in San Sebastián (Spain)]. / Prevalencia actual de asma en escolares en San Sebastián.

OBJECTIVE: To determine the current prevalence of asthma in children aged 6-12 years old in San Sebastian (Guipuzcoa, Spain). PATIENTS AND METHODS: An observational, cross sectional study was performed in 6-12-year-old children in schools. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was employed. Bronchial hyperresponsiveness was investigated using the free running test, with peak expiratory flow (PEF) measured with a peak flow meter as the main measurement. The ISAAC questionnaire (n = 919) was distributed to 460 boys (50.1%) and 459 girls (49.9%) with a mean age of 8 years (SD 1.87). The response rate to the questionnaire was 93 % (n = 855). Participation in the free running test was 90.8% (n = 835). A total of 89.88% of the children (n = 826) completed both tests. RESULTS: The questionnaire of symptoms and signs compatible with asthma revealed a current prevalence of asthma of 25.56% (n = 216) and a cumulative prevalence of 25.44% (n = 85). Nocturnal asthma was found in 29.37% (n = 47) and severe asthma in 9.27% (n = 14). Bronchial hyperresponsiveness was found in 23% of the participants. An epidemiological diagnosis of asthma (asthma-related symptoms plus bronchial hyperresponsiveness) was made in 6.54%. CONCLUSIONS: The current prevalence of asthma in 6-12-year-old schoolchildren in San Sebastian, determined through symptoms and signs compatible with asthma in the previous year and a positive free running test, is similar to that reported in other national studies.

[Clinical characteristics of children hospitalized for influenza virus infection]. / Características clínicas de los niños hospitalizados por infección por virus Influenza.

BACKGROUND: The clinical manifestations of influenza virus are fairly nonspecific and are similar to those of other viral infections, respiratory processes due to other causes and even septic disease in neonates. Few studies have been performed of the clinical characteristics of influenza virus infection in hospitalized children. OBJECTIVE: To evaluate the clinical characteristics of children hospitalized for influenza virus infection in four consecutive epidemic waves (2000-2004). MATERIAL AND METHODS: We retrospectively reviewed the medical records of children hospitalized for influenza A and B virus infection confirmed by cell culture and polymerase chain reaction. Age, sex, symptoms on admission, complementary investigations, diagnosis and outcome were evaluated. RESULTS: Eighty-four children were hospitalized, of which 74 had influenza virus type AH3, five had influenza virus type AH1 and five had influenza B virus. A total of 42.8 % were aged less than 6 months. The main symptoms were fever (75 patients), cough (56 patients) and ENT involvement (53 patients). The most frequent causes of admission were febrile syndrome (75 patients), bronchiolitis (19 patients), pneumonia (13 patients) and bronchitis (8 patients). In 21 patients viral or bacterial coinfection was found, the most frequent of which was respiratory syncytial virus (10 patients). Few differences were found among age groups except for pneumonia and prolonged fever (more frequent in children older than 6 months) and lymphocytosis (in children younger than 6 months). The greatest number of complementary investigations in younger children was performed for acute febrile syndrome in neonates aged less than 6 months. Risk factors for hospitalization were found in only three children, all of whom were older than 6 months. Outcome was favorable in all children. CONCLUSIONS: Influenza virus infection in hospitalized children is most frequent in previously healthy neonates with fever and nonspecific signs and symptoms that are similar to those of other infectious processes. Specific microbiological diagnostic techniques are required for an early diagnosis. Healthy infants aged less than 24 months are most at risk for hospitalization for influenza virus infection.

[The pediatrician and child death: integration of palliative care in the pediatric intensive care unit]. / El pediatra ante la muerte del niño: integración de los cuidados paliativos en la unidad de cuidados intensivos pediátricos.

Palliative care is essential in the pediatric intensive care unit (PICU). Because of the mortality rates and the presence of life-threatening conditions in children admitted to the PICU, pediatricians must be prepared to provide palliative care independently of cure-directed therapies. The present article reviews certain issues, including the decision-making process in the PICU, psychosocial needs and susceptibility to burnout among PICU staff, and the emotions and attitudes of the staff when a child dies. We provide some guidelines on how to act when a child dies, how to meet with parents after the child's death and how to follow-up parental bereavement. Strategies that can help PICU pediatricians to cope with the numerous loses they experience are suggested.

[Validation of a Spanish version of the Childhood Asthma Control Test (Sc-ACT) for use in Spain]. / Validación de la versión en español de la prueba de control del asma infantil (ACT) para su uso en España.

OBJECTIVE: The Childhood Asthma Control Test (c-ACT) is a validated tool for determining pediatric asthma control. However, it is not validated in the Spanish language in Spain. We evaluated the psychometric properties of the Spanish version of the Childhood Asthma Control Test (Sc-ACT) for assessing asthma control in children ages 4 to11. METHODS: This national, multicentre, prospective study was conducted in Spain with asthmatic children and their caregivers. Patients were assessed at 3 visits (Baseline, 2 Weeks, and 4 Months). Clinical variables included: symptoms, exacerbations, FEV1, asthma classification, PAQLQ and PACQLQ questionnaire scores, and asthma control as perceived by physicians, patients and caregivers. The Sc-ACT feasibility, validity, reliability, and sensitivity to change were assessed. RESULTS: A total of 394 children were included; mean (SD) time to complete the Sc-ACT was 5.3 (4.4) minutes. Sc-ACT score was correlated with asthma control as perceived by physician (-0.52), patient (-0.53), and caregiver (-0.51) and with the PAQLQ (0.56) and PACQLQ (0.55) scores. Sc-ACT was found to be significantly related to intensity and frequency of asthma symptoms. Cronbach alpha coefficient α was 0.81 and intraclass correlation coefficient was ≥0.85 for all of the items. The global effect size of Sc-ACT was 0.55. The cutoff point scores of 21 or higher indicated a good asthma control and their MCID was 4 points. CONCLUSION: The Spanish version of the c-ACT was found to be a reliable and valid questionnaire for evaluating asthma control in Spanish-speaking children ages 4 to 11 in Spain.

[Risk assessment in children with lithogenic kidney stones]. / Evaluatión del perfil de riesgo litógeno en niños con litiasis renal.

OBJECTIVE: The aim of this study was to describe the lithogenic risk profile of pediatric patients with lithiasis. METHODS: We retrospectively analyzed the metabolic studies in 24-hour urine samples in 47 pediatric patients with lithiasis. Biochemical determinations were made in blood and 24-hour urine. Oxalate calcium, brushite, struvite and uric acid salt saturations were calculated. 49 healthy children were used as a control group. RESULTS: No significant differences were found in biochemical blood parameters between children with stones and the group without stones. Calciuria, uricosuria and phosphaturia, oxalate calcium, brushite and uric acid saturations were higher in lithiasic children. In the multivariate analysis, using a logistic regression model, we only found hypercalciuria as lithogenic risk factor. (OR = 1.96 p <0.002). CONCLUSIONS: Urinary metabolic abnormalities and elevated salt saturations in urine are a frequent finding in children with urolithiasis, but in our study we only found hypercalciuria as an independent risk factor for the formation of lithiasis.

[Psychogenic cough: Another etiology for persistent cough]. / Tos psicógena: una causa de tos crónica.

The most common causes of persistent cough are upper respiratory tract disease (postnasal drip syndrome, infections) and asthma. In the last year, six patients (four boys and two girls), aged 7-12 years old, with a diagnosis of hard-to-manage asthma and/or persistent cough were referred to our department. All the patients had undergone treatment with multiple drugs for long periods without favorable clinical response. The findings of physical examination, radiology, basal pulmonary function and post-bronchodilation and fibrobronchoscopy were normal. Organic disease was ruled out and a psychiatric evaluation was performed. Intelligence quotient was in the lower normal range and generalized anxiety order was identified, thus establishing a diagnosis of psychogenic cough. Treatment consisted of relaxation techniques and psychopedagogic support with favorable outcome. To avoid diagnostic errors and inappropriate treatment, psychogenic cough should be included in the differential diagnosis of persistent cough and hard-to-manage asthma.

[Erythema nodosum: etiological changes in the last two decades]. / Eritema nudoso: modificación etiológica en las dos últimas décadas.

OBJECTIVE: To study the etiological factors associated with erythema nodosum in children hospitalized between January 1985 and December 2003. MATERIAL AND METHODS: We performed a retrospective, descriptive study through review of the medical records of children with a diagnosis of erythema nodosum (MBDS-ICD 9-CM, code 6952). Forty-five patients (27 boys and 18 girls) aged between 10 months and 14 years were studied. The following variables were analyzed: age, sex, associated symptoms, complementary investigations (blood count, erythrocyte sedimentation rate, throat swab, chest x-ray, Mantoux test, ASLO titer, stool culture, serology) and final diagnosis. RESULTS: The most frequent etiology was tuberculosis (10 patients), followed by Salmonella enteritidis (7 patients), group A beta -hemolytic Streptococcus (3 patients), Salmonella typhimurium (2 patients), Campylobacter jejuni (2 patients), Yersinia enterocolitica (1 patient), infectious mononucleosis caused by Epstein Barr virus (1 patient), cat scratch disease (1 patient), BCG vaccination (1 patient), associated chronic hepatitis B infection (1 patient), and associated amoxicillin treatment (1 patient). Etiology was unknown in 15 patients. The last case of erythema nodosum associated with tuberculous infection dated back to 1991, after which the most frequent etiologic factors associated with erythema nodosum were gastrointestinal pathogens. CONCLUSIONS: According to our results, the main etiological factor currently associated with erythema nodosum is gastrointestinal infection. Consequently, stool cultures, especially when there are associated gastrointestinal symptoms, are essential.