Progressive familial intrahepatic cholestasis (PFIC) is rare genetic liver disorders that often present with early-onset cholestasis, pruritus, and potential progression to severe liver complications. This article outlines consensus recommendations for the diagnosis and management of PFIC tailored to Latin American healthcare providers. A working group of 10 hepatologists across Latin America utilized the Population, Intervention, Comparison, and Outcome (P.I.C.O.) framework to address critical clinical questions related to PFIC's epidemiology, diagnosis, and treatment. A systematic literature review was conducted to understand the disease's heterogeneous nature and its impact on patients' quality of life. The consensus emphasizes early referral to specialists, the importance of genetic testing for definitive diagnosis, and individualized treatment approaches with medical therapies including ursodeoxycholic acid and novel ileal bile acid transport inhibitors. Surgical options, including liver transplantation, should be considered based on disease sub-types. The article also highlights challenges unique to Latin America, such as limited access to specialized care and genetic testing. Early diagnosis and a comprehensive, individualized management plan are essential for improving outcomes in PFIC patients. This consensus aims to increase awareness and understanding of PFIC among healthcare providers.

Alopecia areata (AA) in children is associated with comorbidities such as atopy, vitiligo, psoriasis, and thyroid disease, but reported data are lacking. Our objective is to estimate the frequency of comorbidities present in children with AA, as well as their relationship with age of onset, specific subtype, and treatment efficacy. We retrospectively reviewed clinical records of patients treated at the National Institute of Pediatrics between 2008 and 2018. Patients were categorized into subgroups: localized versus non-localized AA, onset in preschool age (< 7 years) versus school age (≥ 7 years), and treatment response as good (≥ 50% regrowth) versus suboptimal (< 50%). Comorbidities were classified as autoimmune, inflammatory/reactive, congenital, psychological, infectious, and neoplastic. We included 105 patients diagnosed with AA. The most prevalent subtype was localized in 78 (74.3%) patients. Ninety-five (90%) patients had comorbidities, with allergic rhinitis (n = 12, 11.4%) and atopic dermatitis (n = 11, 10.4%) being the most frequent. Autoimmune comorbidities occurred in 16 patients (15.2%), with autoimmune thyroid disease being the most prevalent in 8 patients (7.6%). Localized AA was associated with better outcomes, shorter duration, fewer relapses, and fewer treatments, as well as inflammatory and congenital diseases. The association of AA with atopic, autoimmune, and psychiatric comorbidities is consistent with literature reports. Our findings support intentionally seeking associated diseases in pediatric patients with AA to identify them and treat them timely.

Among the various etiologies related to the presence of abdominal masses in newborns, the diagnosis of fetus in fetu (FIF), a term used to describe a congenital condition in which one fetus parasitizes the body, should be considered. We present the case of a male newborn who was found to have an abdominal mass during perinatal evaluation, leading to termination of pregnancy by cesarean section. After a thorough evaluation, a protocol was established that resulted in surgical intervention and the diagnosis of FIF. FIF is an exceptionally rare entity characterized by the presence of a "parasitic twin." Its pathophysiology and risk factors remain poorly understood, but it must be considered in the differential diagnosis of neonatal abdominal masses. Owing to its rarity, standardized follow-up protocols have not been established. Nevertheless, with current advances in pediatric surgery, the prognosis after complete excision is favorable.

The relationship between abdominal fat depots and cardiometabolic risk among youth is inconclusive due to the cross-sectional nature of existing studies and limitations in assessment methods. In this study, we examined cross-sectional and longitudinal associations of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) with cardiometabolic risk indicators among Mexican adolescents. Participants (n = 169 at baseline and 134 at follow-up) were assessed for diastolic or systolic blood pressure (DBP or SBP), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, glucose, and insulin. VAT and SAT were measured using magnetic resonance imaging. Measures were repeated at 1-year follow-up. Using multilevel linear regression models, the associations among fat depots and cardiometabolic risk indicators were examined. At baseline, SAT measures were cross-sectional and positively associated with glucose, insulin, TC, triglycerides, SBP, and BDP in boys, and DBP in girls, but negatively with HDL-C. VAT measures were cross-sectional and positively associated with glucose, insulin, and SBP and DBP in boys. VAT at L1-L2 was longitudinal and positively associated with insulin, TC, LDL-C, and DBP in boys. Higher levels of SAT and increases in VAT during adolescence may be particularly detrimental to cardiometabolic health, contributing to an increased risk of future diseases. Future intervention and treatment strategies should target VAT to reduce disease risk in this population.

Una causa poco frecuente de morbilidad en el recién nacido son las malformaciones congénitas del tracto respiratorio. Muchas de ellas pueden tener un origen común, es por ello que existe la posibilidad de que se presenten en conjunto, lo que se conoce como malformación pulmonar híbrida. La aparición conjunta de secuestro pulmonar y malformación adenomatoidea quística se ha descrito en muy pocos casos, aproximadamente 40-60 pacientes desde el primer caso reportado en 1949. Secuestro pulmonar se define como tejido quístico pulmonar ectópico no funcionante, con vascularización arterial propia de origen sistémico. Es una enfermedad congénita infrecuente, de presentación clínica variable, que puede ser intralobar o extralobar, y se puede acompañar de otras malformaciones, como en el caso de la enfermedad adenomatosa congénita. En la mayoría de los casos el tratamiento es quirúrgico y consiste en resecciones lobares por medio de videotoracoscopia. Paciente de 7 días de vida que al nacer inicia con dificultad respiratoria grave, requiriendo ventilación mecánica invasiva. Identifican derrame pleural y neumotórax izquierdo, por lo que colocan tubo de toracostomía, sin embargo, no resuelve completamente. Parte la sospecha clínica de malformación congénita pulmonar, la cual se confirma por medio de tomografía computarizada pulmonar y angiotomografía pulmonar, la cual evidencia vaso accesorio de origen aórtico, por lo que se realiza tratamiento quirúrgico. La resección temprana puede ser beneficiosa para el crecimiento pulmonar. A rare cause of morbidity in the newborn is congenital malformations of the respiratory tract. Many of them can have a common origin, which is why there is the possibility of presenting them together, known as hybrid pulmonary malformation. The joint appearance of pulmonary sequestration and cystic adenomatoid malformation has been described in very few cases, approximately 40-60 patients since the first case reported in 1949. Pulmonary sequestration is defined as ectopic nonfunctioning pulmonary cystic tissue, with its own arterial vascularization of systemic origin. It is a rare congenital disease, with variable clinical presentation, which can be intralobar or extralobar, and may be accompanied by other malformations as in the case of congenital adenomatous disease. In most cases the treatment is surgical, consisting of lobar resections through video thoracoscopy. Seven-day-old patient who at birth begins with severe respiratory difficulty requiring invasive mechanical ventilation. Left pleural effusion and pneumothorax are identified, so a thoracostomy tube is placed, however, it does not completely resolve, the clinical suspicion of congenital pulmonary malformation arises, which is confirmed by means of pulmonary computed tomography and pulmonary angiography, which shows accessory vessel of aortic origin for which surgical treatment is performed. Early resection may be beneficial for lung growth.

The neonatal microbiota plays a central role in shaping gastrointestinal and immune system maturation, laying the foundation for lifelong health. Prenatally, bacteria in the amniotic fluid and meconium, likely derived from the maternal microbiota, prime the fetal immune system to tolerate beneficial microbes postnatally. At birth, the neonate acquires its initial microbiota through the birth canal or environmental exposure, with breast milk delivering human milk oligosaccharides that selectively nourish beneficial bacteria, such as Lactobacillus and Bifidobacterium, fostering a protective gut microbiota. Meconium in the colon further supports this process by acting as a barrier against pathogens while promoting colonization by commensal microbes. These early microbial communities enhance intestinal barrier function through tight junction maturation, reduce permeability, and bolster immune defenses, mitigating infection risks. As infants transition to solid foods, microbial diversity increases, supporting intestinal villi development, nutrient absorption, and dietary adaptability. By approximately 3 years of age, the gut microbiota stabilizes, driving critical roles in digestion, vitamin synthesis, and inflammation regulation. This review synthesizes current evidence on the dynamic interaction and influence of maternal factors and breast milk composition on neonatal microbiota development, highlighting current insights into their implications for the infant's immune system and gastrointestinal development.

La luxación congénita de rodilla (LCR) es una anomalía musculoesquelética poco frecuente, caracterizada por hiperextensión de la rodilla al nacimiento. Sus posibles causas incluyen factores mecánicos, como el oligoamnios o la presentación podálica, así como alteraciones genéticas o neuromusculares. El objetivo fue describir la incidencia, características clínicas, tratamiento y resultados de los casos de LCR diagnosticados en una unidad neonatal del norte de España durante un periodo de 20 años. Se llevó a cabo un estudio observacional, descriptivo y retrospectivo de casos de LCR diagnosticados entre 2005 y 2024 (43,500 nacimientos). Se analizaron variables demográficas, obstétricas, clínicas, terapéuticas y de complicaciones, obtenidas de los historiales clínicos e imágenes diagnósticas. Se identificaron ocho pacientes (11 rodillas afectadas), con una incidencia del 0.02%. La edad gestacional media fue de 37 semanas y el peso medio al nacer de 2,435 gramos. El 75% de los casos correspondieron a niñas, con afectación bilateral en el 37.5% y predominio de la rodilla izquierda. Se observó oligoamnios en el 25% y presentación podálica en el 37.5% de los casos. La displasia del desarrollo de cadera fue la comorbilidad más frecuente (37.5%). Todos los pacientes fueron tratados de forma conservadora mediante yesos seriados, con resultados favorables en seis de ellos. Un caso requirió tratamiento ortésico prolongado por malformaciones complejas y otro presentó una leve discrepancia en la longitud de las extremidades. El diagnóstico precoz, habitualmente mediante exploración física, es esencial para un pronóstico favorable. El tratamiento conservador resulta eficaz en la mayoría de los casos, reservándose la cirugía para situaciones refractarias. La incidencia observada fue superior a la descrita clásicamente, lo que podría reflejar variaciones metodológicas o poblacionales. La evaluación integral de los pacientes es fundamental para identificar anomalías asociadas y prevenir complicaciones a largo plazo.

In Mexico, childhood cancer is the leading cause of death by disease in children between 5 and 14 years of age, and the sixth leading cause of death in children under 5 years of age. In addition, it represents almost 70% of the total cancer burden in the pediatric population. It comprises a heterogeneous group of malignancies with different clinical patterns, etiologies, therapeutic options, and survival prognoses. Descriptive cross-sectional study that included confirmed cases of childhood cancer in patients between 1 and 18 years of age, diagnosed with hematolymphoid neoplasms and solid tumors. The study was carried out in a third-level hospital of the Instituto Mexicano del Seguro Social UMAE N71, located in northwest Mexico, during the year 2024. The International Classification of Childhood Cancer, third edition (ICCC-3), was used for the analysis and classification of cases. The mean age of the patients was 8 years, with a distribution of 40.4% in females and 59.5% in males. Leukemia was the most common pediatric cancer, with acute lymphoblastic leukemia standing out in 45% of cases. This was followed by solid tumors in the central nervous system (CNS), representing 20.2%, the most frequent being astrocytomas, ependymomas, and other types of gliomas. Leukemias and CNS tumors were identified as the most frequent types of childhood cancer in the northwestern region of Mexico. The use of the classification (ICCC-3) represents a fundamental tool for the standardization of diagnosis and epidemiological analysis of childhood cancer.

In Ibero-Latin America, the use of probiotics in pediatrics has increased in recent decades; however, clinical practice shows significant variability across countries and specialties. This situation prompted the development of a regional consensus based on the best available evidence and expert experience. To develop an Ibero-Latin American clinical practice guideline on the use of probiotics in pediatric gastroenterology, hepatology, and nutrition. A multidisciplinary panel of specialists from 12 countries, including gastroenterologists, hepatologists, nutritionists, and pediatricians, was convened. A systematic literature review was conducted in PubMed, Scopus, and Cochrane Library through December 2023. Evidence was assessed using the GRADE methodology, and key clinical questions were formulated. Recommendations were discussed and refined through a three-round Delphi process until consensus was reached. Specific recommendations were developed for the use of probiotics in acute diarrhea, antibiotic-associated diarrhea, gastrointestinal infections, functional gastrointestinal disorders, and inflammatory diseases. Strains and doses with proven efficacy, such as Lactobacillus rhamnosus GG and Saccharomyces boulardii, were identified, and clinical scenarios where probiotic use is not justified were defined. The final consensus incorporated considerations of safety, applicability, and regional context. This guideline represents the first Ibero-Latin American collaborative effort to unify criteria for the use of probiotics in pediatrics, providing a practical and evidence-based framework to improve clinical care across the region.