Search

Existen cuatro tipos de receptores histaminérgicos. Los síntomas de alergia, especialmente rinoconjuntivitis alérgica y urticaria, son principalmente causados por activación del receptor H1; por ende, los antihistamínicos H1 orales (anti-H1) forman parte integral del tratamiento de estas enfermedades. Los antihistamínicos son agonistas inversos, porque estabilizan la forma inactiva del receptor. Los antihistamínicos H1 de primera generación producen efectos adversos por varios mecanismos: sedación (fijación a receptores H1 cerebrales), boca seca, retención urinaria, aumento de peso (baja selectividad: estimulación de los receptores de serotonina, muscarina y alfa-adrenérgicos) e interacciones medicamentosas (con sustrato de citocromo P450-3A4). Los antihistamínicos H1 de segunda generación son generalmente más seguros. Las nuevas guías de tratamiento de la rinitis alérgica y urticaria recomiendan como manejo de primera intención a los antihistamínicos H1 de segunda generación. En urticaria se recomienda hasta cuadruplicar su dosis en caso necesario. El aumento de la eficacia en el control de la urticaria con cuádruple dosis, sin que se afecte la seguridad, se ha documentado para bilastina, desloratadina y levocetirizina (rupatadina). Respecto de ebastina y fexofenadina, hasta ahora, sólo se comprobó la seguridad de cuádruple dosis. Una rigurosa excepción son astemizol y terfenadina, que a concentraciones séricas elevadas pueden causar taquicardia ventricular. No se recomiendan los antihistamínicos H1 de primera generación y aumentar su dosis no es seguro.

El bienestar psicológico se refiere a la satisfacción general que los individuos tienen respecto de su vida. Este concepto se ha relacionado con la salud mental y con la detección de factores favorables al desarrollo humano. El interés en su estudio en adolescentes se ha incrementado en los últimos años debido a los cambios físicos, mentales y sociales propios a esta etapa del desarrollo, por lo que son necesarios instrumentos válidos y confiables que permitan su evaluación. El objetivo de este estudio fue evaluar propiedades psicométricas de la Escala de Bienestar Psicológico para Adolescentes (BIEPS-J) en una muestra mexicana de adolescentes tardíos y obtener evidencia de su validez convergente y de criterio. Se aplicó la escala BIEPS-J y la Escala de Autoestima de Rosenberg (EAR) a 271 estudiantes de ambos sexos de entre 16 y 18 años. Un análisis paralelo indicó dos factores presentes en la escala BIEPS-J, estructurados mediante un análisis factorial exploratorio (componentes principales, rotación oblicua) y que explicaron el 54% de la varianza. Los factores fueron: 1) Relación con uno mismo y con terceros, satisfacción con sus relaciones sociales y la aceptación de sí mismo; 2) Planes y recursos personales de control, sensación del dominio de su entorno y auto-competencia, además de la presencia de metas en su vida. La consistencia interna global (α > .80) y por factor (α > .70) fue aceptable. La escala BIEPS-J mostró validez convergente con la EAR (r = .44) y el nivel de bienestar psicológico se asoció al nivel de autoestima (p < .001). El puntaje total y por factor de la escala BIEPS-J no difirió entre sexos (p > .05). Los datos indican que la escala BIEPS-A es un instrumento válido y confiable para evaluar el bienestar psicológico en población adolescente mexicana de entre 16 y 18 años.

BackgroundPediatric inflammatory multisystem syndrome (PIMS) is a complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children that resembles Kawasaki syndrome and places them at high risk of cardiorespiratory instability and/or cardiac damage. This study aims to describe the clinical presentation and outcomes of patients with PIMS in Mexico City.MethodsThis was an observational study of children hospitalized for PIMS based on the Centers for Disease Control and Prevention case definition criteria, in a single tertiary care pediatric center in Mexico City between May 1, 2020, and September 30, 2021. Demographic characteristics, epidemiological data, medical history, laboratory tests, cardiologic evaluations, treatment, and clinical outcomes were analyzed.ResultsSeventy-five cases fulfilled the case definition criteria for PIMS [median age: 10.9 years, Interquartile range (IQR): 5.6–15.6]. Fifteen (20%) patients had a severe underlying disease, 48 (64%) were admitted to the intensive care unit, 33 (44%) required invasive mechanical ventilation and 39 (52%) received vasopressor support. The patients were clustered through latent class analysis based on identified symptoms: Cluster 1 had rash or gastrointestinal symptoms (n = 60) and cluster 2 were those with predominantly respiratory manifestations (n = 15). Two patients (2.7%) died, and both had severe underlying conditions. Five patients (6.7%), all from cluster 1, developed coronary aneurysms.ConclusionThere were a high proportion of patients with severe respiratory involvement and positive RT-PCR SARS-CoV-2 and very few cases of coronary aneurysms in our study which suggests that a high proportion of the children had severe acute COVID-19. The clinical manifestations and outcomes are comparable to previously reported international studies.

BackgroundAsthma is a common but complex disease with racial/ethnic differences in prevalence, morbidity, and response to therapies.ObjectiveWe sought to perform an analysis of genetic ancestry to identify new loci that contribute to asthma susceptibility.MethodsWe leveraged the mixed ancestry of 3902 Latinos and performed an admixture mapping meta-analysis for asthma susceptibility. We replicated associations in an independent study of 3774 Latinos, performed targeted sequencing for fine mapping, and tested for disease correlations with gene expression in the whole blood of more than 500 subjects from 3 racial/ethnic groups.ResultsWe identified a genome-wide significant admixture mapping peak at 18q21 in Latinos (P=6.8×10-6), where Native American ancestry was associated with increased risk of asthma (odds ratio [OR], 1.20; 95% CI, 1.07-1.34; P=.002) and European ancestry was associated with protection (OR, 0.86; 95% CI, 0.77-0.96; P=.008). Our findings were replicated in an independent childhood asthma study in Latinos (P=5.3×10-3, combined P=2.6×10-7). Fine mapping of 18q21 in 1978 Latinos identified a significant association with multiple variants 5' of SMAD family member 2 (SMAD2) in Mexicans, whereas a single rare variant in the same window was the top association in Puerto Ricans. Low versus high SMAD2 blood expression was correlated with case status (13.4% lower expression; OR, 3.93; 95% CI, 2.12-7.28; P&nbsp

Simple Summary Neuroblastoma (NB) presents diverse biological and clinical characteristics, from spontaneous regression to highly malignant and aggressive unfavorable tumors that condition the therapeutic failure of conventional treatments. The tumorigenesis of NB can be the result of different genetic variants, which can influence the clinical outcome, and the survival of patients who have metastatic tumors is low. The role of cytokines such as interleukin (IL)-6 has been described in the NB microenvironment promoting tumor progression and metastasis. Single nucleotide polymorphism (SNP)-174 G > C in IL-6 and -251 T > A and +781 C > T in IL-8 regulate the expression of these cytokines, and could be associated with the clinical outcome in patients with NB. Our objective was to evaluate the association of the genetic polymorphisms of IL-6 and IL-8, as well as the serum levels of these cytokines in patients with NB, as this will allow the genetic bases of NB to be characterized and understood, in order to predict the outcome of the disease and develop new therapeutic strategies. Abstract There is evidence that high circulating levels of IL-6 and IL-8 are markers of a poor prognosis in various types of cancer, including NB. The participation of these cytokines in the tumor microenvironment has been described to promote progression and metastasis. Our objective was to evaluate the prognostic role of genetic polymorphisms and serum levels of IL-6 and IL-8 in a cohort of Mexican pediatric patients with NB. The detection of the SNPs rs1800795 IL-6 and rs4073 and rs2227306 IL-8 was carried out by PCR-RFLP and the levels of cytokines were determined by the ELISA method. We found elevated circulating levels of IL-8 and IL-6 in NB patients compared to the control group. The genotype frequencies of the rs1800795 IL-6 and rs4073 IL-8 variants were different between the patients with NB and the control group. Likewise, the survival analysis showed that the GG genotypes of rs1800795 IL-6 (p = 0.014) and AA genotypes of rs4073 IL-8 (p = 0.002), as well as high levels of IL-6 (p = 0.009) and IL-8 (p = 0.046), were associated with lower overall survival. We confirmed the impact on an adverse prognosis in a multivariate model. This study suggests that the SNPs rs1800795 IL-6 and rs4073 IL-8 and their serum levels could be promising biomarkers of a poor prognosis, associated with overall survival, metastasis, and a high risk in Mexican children with NB.

Overview of the pandemic In December 2019, a new virus named SARS-CoV-2 was reported in Wuhan province, China. The first case of COVID-19 in Mexico was confirmed on February 28, 2020, and the World Health Organization declared the pandemic on March 11.

In the early years of the 20th century, no hospital in Mexico held the capacity to address the health problems of Mexican children, making it necessary to build a modern institution to take care of these issues. This situation mobilized a group of doctors led by Dr. Federico Gomez Santos to seek the acknowledgement of the President, Abelardo L. Rodriguez, of the urgent need of a children's hospital. Later, the President approved the project for its construction in 1933. After 10 years of struggle in the political, social and economic fields, and with the support of presidents Lazaro Cardenas and Manuel Avila Camacho, the Hospital Infantil de Mexico was inaugurated on April 30th, 1943. Today, 75 years after its creation, the hospital has withstood the test of time maintaining intact its principles of assistance, teaching and research, and emerging as the cradle of Mexican and Latin American pediatrics.

Background: According to the International Study of Asthma and Allergies in Childhood (ISAAC) methodology, in 2003, the prevalence of asthma symptoms in children 6–7 years old and adolescents 13–14 years old was 11.6% and 13.7%, respectively. Since then, the number of asthma cases has increased worldwide. The study was conducted in several districts in northern Mexico City to evaluate the prevalence of asthma in these age groups and examine possible risk factors. The data were compared to the 2003 results from the same area. Methods: This was a comparative cross-sectional study following the official Global Asthma Network (GAN) methodology. The parents or guardians of participants completed a questionnaire that explored demographics, asthma symptoms, diagnoses, and possible risk factors. Central tendency measurements were determined for statistical analysis and chi-squared distribution for possible risk factors. Results: A total of 2515 children aged 6–7 years and 3375 adolescents aged 13–14 years participated in the study. Compared to the ISAAC results, we found a greater prevalence of wheezing in both children (at some time in life, 19.2% vs. 27.1%; over the last year, 6.8% vs. 10.6%) and adolescents (at some time in life, 16.9% vs. 19.7%), and for children with an asthma diagnosis (4.5% vs. 5.1%). For both groups, the most common risk factor associated with wheezing was the presence of rhinitis symptoms. Conclusions: Asthma symptoms are highly prevalent in Mexico City, occurring in almost 20% of adolescents. Compared to a decade ago, there was a 7.9% increase in the prevalence of asthma symptoms in children. Almost half of the children and adolescents presenting with symptoms had experienced more than four episodes per year. However, less than 50% of children and adolescents with asthma symptoms had been diagnosed with this disorder, suggesting under-diagnosis. Keywords: Asthma, Atopic allergic diseases, Wheezing, Rhinitis, Risk factors, ISAAC, GAN

Inhaled therapy is considered the cornerstone of asthma treatment. However, despite being the ideal form of drug delivery, it is recognized that only 70% of patients have an adequate attachment to their treatment and only 39-67% of physicians can explain the optimal inhaler technique. Inhaled therapy has very specific characteristics. Pulmonary deposit of an inhaled medication through the respiratory tract is more complex than when administered orally and depends on several factors inherent to both the medication and the administration. For successful inhaled therapy, the drug needs to be converted into particles of an appropriate size, which can enter beyond the oropharynx and larynx, and be deposited in the lungs. There are multiple devices for the administration of drugs in the lower respiratory tract, each one with a similar efficacy as long as it is used with the correct technique. The decision of which device should be used is made based on the age of the patient, the ability to coordinate between the inhalation and activation of the device, and the presence of acute symptoms. The choice of the device must be evaluated individually.La terapia inhalada se considera la piedra angular del manejo del asma. Sin embargo, a pesar de ser la forma ideal de administración de estos medicamentos, solamente el 70% de los pacientes cumple el tratamiento adecuadamente y sólo del 39 al 67% de los médicos conocen y pueden explicar de forma adecuada las distintas técnicas de inhalación. La terapia inhalada tiene características muy particulares. El depósito pulmonar de un medicamento inhalado a través del tracto respiratorio es más complejo que cuando se administra por vía oral, y varía dependiendo de varios factores, tanto inherentes al medicamento como a la forma de administrarlo. Para que la terapia inhalada sea exitosa, se requiere que se generen partículas del medicamento de un tamaño apropiado que penetren más allá de la orofaringe y la laringe, y que puedan depositarse en los pulmones. Existen múltiples dispositivos para la administración de medicamentos en la vía respiratoria baja. Cada uno ha probado tener una eficacia similar, siempre y cuando se utilicen con la técnica correcta. La decisión para su uso se realiza con base en la edad del paciente, la capacidad de coordinar entre la inhalación y la activación del dispositivo y la presencia de síntomas agudos. La elección del dispositivo a utilizar siempre deberá hacerse de forma conjunta, evaluando pros y contras de cada uno de los dispositivos y siempre de forma individualizada.

Asthma is the most frequent chronic inflammatory lung disease of childhood Exacerbations should be treated with short acting beta-2 agonist and systemic steroids Long-term control should be based on the symptoms prior to the crisis When the patient first presents with acute exacerbation with no history of disease severity prior to the attack, treatment should at least start on level 3 (Tebo et al., Pediatr Rheumatol Online J 10:29, 2012; Adkinson and Middleton, Middleton’s allergy: principles and practice, 2013; Castro-Rodriguez et al., Am J Respir Crit Care Med 162(4 Pt 1):1403–6, 2006; Larenas-Linnemann et al., Rev Alerg Mex. 64(Suppl 1):s11-s128, 2017).

Asthma and allergic rhinitis frequently appear together Otitis media, upper respiratory tract infections and sinusitis are frequent comorbidities of allergic rhinoconjunctivitis Persistent allergic rhinitis is defined as having symptoms for more than 4 days a week and for over 4 weeks

Allergic rhinitis is the most common form of non-infectious rhinitis Intranasal corticosteroids are superior to oral antihistamines or leukotriene receptor antagonists to control all aspects of allergic rhinitis Asthma is the most frequent comorbid condition with allergic rhinitis

Short-acting beta-2 agonists administered up to 4–10 puffs every 20 min for the first hour, is the most effective way to break an asthma attack Over-use of beta-2 agonists and solo use of beta-2 agonists, history of hospitalization or emergency care visit for asthma, or intensive care unit admissions due to asthma in the past year, and poor adherence to medications, predict mortality in asthma

Introducción: El asma en un problema de salud pública en el mundo, por ello, la actualización de las guías para el diagnóstico y tratamiento de asma se realiza en función principalmente de la práctica de los médicos de primer contacto. Las intervenciones educativas son útiles para el incremento del conocimiento.Objetivo: Comparar el nivel de conocimiento acerca de asma antes y después de una intervención educativa.Métodos: Se realizó un estudio prospectivo cuasiexperimental, en médicos generales, familiares y pediatras que asistieron a un curso-taller relativo a aspectos generales del asma y las guías actuales para su diagnóstico y tratamiento (GINA 2014). Mediante un cuestionario constituido por 11 preguntas de opción múltiple que abordaban aspectos fundamentales de la enfermedad como diagnóstico, clasificación, tratamiento y manejo de exacerbaciones, se realizaron dos evaluaciones, una basal y otra posintervención.Resultados: Un total de 178 paciente participaron en el estudio, con un conocimiento preintervención de 25.5 puntos y posintervención de 97.5 puntos de una escala de 100, con una p

Antecedentes: si bien se cuenta con información epidemiológica de las inmunodeficiencias primarias, la información disponible en México es escasa.Objetivos: dar información epidemiológica del retraso del diagnóstico de las inmunodeficiencias primarias y de su correlación con daño pulmonar crónico.Material y método: estudio retrospectivo, analítico, efectuado en pacientes de 0 a 18 años de edad con diagnóstico de inmunodeficiencias primarias durante 11 años en el Hospital Infantil de México Federico Gómez; las variables estudiadas fueron: edad al inicio de los síntomas, edad al diagnóstico, tiempo desde el inicio de los síntomas al diagnóstico, número de neumonías previas y estudios radiográficos con datos de daño pulmonar crónico.Resultados: se incluyeron 48 pacientes que cumplieron los criterios de inclusión; 33 tenían daño pulmonar al diagnóstico, el déficit de anticuerpos fue el grupo con mayor afectación. Al correlacionar la edad de inicio de los síntomas y la diferencia de tiempo del inicio de los síntomas al diagnóstico se obtuvo una fuerte correlación (p 0.80). Se observó una correlación moderada entre la diferencia en tiempo vs número de neumonías (p=0.005, Rho=0.495) y la correlación entre número de neumonías y daño pulmonar mostró significación alta (p

Background: The global prevalence of allergic rhinitis is high. International Study of Asthma and Allergies in Childhood (ISAAC) Phase III reports a total estimated prevalence of 4.6% in Mexico. There is evidence based on allergic rhinitis Clinical Practice Guidelines (CPG), but its promotion, acceptance and application is not optimal or adequate in Mexico. Objective: To generate a guideline for the treatment of allergic rhinitis and its impact on asthma by adaptating the 2010 ARIA Guideline to Mexican reality, through a transculturation process applying the ADAPTE methodology. Material and method: Using the ADAPTE Methodology, the original 2010 ARIA CPG recommendations were evaluated by the guideline development group (GDG) into which multiple medical specialities managing patients with allergic rhinitis were incoorporated. The GDG valorated the quality of 2010 ARIA, checked and translated key clinical questions. Moreover, the GDG adjusted recommendations, patient preferences and included comments in the context of the Mexican reality (safety, costs and cultural issues). To accomplish this, we ran Delphi panels with as many rounds as necessary to reach agreement. One extra question, not included in the original 2010 ARIA, on the use of Nasal Lavages for AR was created sustained by a systematic literature review. Results: A total of 45 questions from the original 2010 ARIA were included and divided into six groups covering prevention, medical treatment, immunotherapy and alternative medicine to treat patients with allergic rhinitis with or without asthma. Most of the questions reached agreement in one or two rounds; one question required three rounds. Conclusions: An easy-to-use, adaptated, up-to-date and applicable allergic rhinitis guideline for Mexico is now available.

Background: Urticaria is a disease that a fth of the population shall suffer once in a lifetime. Recent clinical guidelines have proposed some fundamental changes in the diagnosis and treatment of urticaria, making the development of a national, multidisciplinary guideline, with wide acceptability among different professional groups –both specialists and primary health care workers–, necessary in Mexico. Material and method: Internationally recognized tools for guideline- development were used. An interdisciplinary group of clinical experts (some of them knowledgeable in methodology of guideline develop - ment) determined the objectives and scope of the Evidence Based Clinical Practice Guideline with SCOPE. It was decided to adapt and transculturize international guidelines on the diagnosis and treatment of urticaria. With AGREE-II three high-quality guidelines (Zuberbier 2014, Sanchez-Borges 2012, Powell 2007) were selected to function as basic guidelines (BG). A set of Clinical Questions was formulated that lead to recommendations/suggestions, based on these BG, taking into account the cultural and economic background of Mexico, according to GRADE recommendation development. Results: By a formal process of discussion and voting during several working-sessions, experts and rst level healthcare physicians deter - mined the wording of the nal guideline, taking particularly care of developing a document, adjusted to the reality, values and preferences of the Mexican patients. The use of oral second generation, non-sedating antihistamines as rst line treatment is emphasized. Conclusion: This document is an Evidence Based Clinical Practice Guideline for the diagnosis and treatment of acute and chronic urticaria, based on three, high quality, international guidelines. It was developed by a multidisciplinary group. Tables and algorithms make the guideline user-friendly for both, rst line health care physicians and specialists

Antecedentes: la alergia a las proteínas de la leche de vaca es la alergia alimentaria más común entre los niños menores de dos años y se asocia con otras enfermedades atópicas.Objetivo: evaluar la frecuencia de alergia a las proteínas de la leche de vaca en pacientes sensibilizados a las mismas, que acuden a la consulta de Inmunología y Alergia del Hospital Infantil de México Federico Gómez, así como su asociación con otras enfermedades atópicas.Material y método: estudio retrolectivo, analítico y descriptivo en el que se revisaron los expedientes clínicos de pacientes de 0 a 19 años de edad, atendidos en la consulta de Inmunología y Alergia del Hospital Infantil de México Federico Gómez, de enero de 2010 a enero de 2013, sensibilizados a las proteínas de leche de vaca por estudios in vitro o in vivo, mediada o no mediada por IgE, para determinar su asociación con otras enfermedades atópicas durante el curso de su evolución clínica.Resultados: se incluyeron 252 pacientes con síntomas sugerentes de alergia a las proteínas de la leche de vaca, de los que sólo en 15.1% se diagnosticó por reto oral. Con respecto a los síntomas respiratorios, alrededor de 66% de los pacientes manifestó rinorrea, obstrucción y prurito nasales. En cuanto a los síntomas gastrointestinales, cerca de 30% tuvo diarrea y dolor y distensión abdominales, lo que fue estadísticamente significativo. El síntoma dermatológico más frecuente y estadísticamente significativo fue la xerosis. Las enfermedades atópicas asociadas con más frecuencia fueron: alergia alimentaria (76.3%), rinitis alérgica (65.8%), asma (47.4%) y dermatitis atópica (23%).Conclusiones: la alergia a las proteínas de la leche de vaca puede asociarse con otras enfermedades atópicas, como alergia a otros alimentos, rinitis alérgica, asma y dermatitis atópica.

The population structure of Native Mexicans The genetics of indigenous Mexicans exhibit substantial geographical structure, some as divergent from each other as are existing populations of Europeans and Asians. By performing genome-wide analyses on Native Mexicans from differing populations, Moreno-Estrada et al. successfully recapitulated the pre-Columbian substructure of Mexico. This ancestral structure is evident among cosmopolitan Mexicans and is correlated with subcontinental origins and medically relevant aspects of lung function. These findings exemplify the importance of understanding the genetic contributions of admixed individuals. Science , this issue p. 1280

Background: There have been reported some reviews and position papers of international societies concerning to perioperative hypersensitivity reactions in adult patients, However the information in the pediatric patient is very limited. Objectives: Updated review on the identification, diagnosis and management of perioperative hypersensitivity reactions in pediatrics. Methods: Search of the literature from 1980 through Medline database. Results: The correct treatment of perioperative hypersensitivity reactions are based on the suspected diagnosis, signs and symptoms, and time of occurrence. Latex, neuromuscular blocking agents (NMBA) and antibiotics are most often associated with immediate hypersensitivity reactions in anesthetic / surgical events. The Ring-Messmer classification can help to categorize perioperative hypersensitivity reactions and provide proper treatment. The adrenaline is the first-line drug in the management of hypersensitivity reactions grade II or higher by Ring-Messmer classification/ or when the patient meets clinical anaphylaxis scenarios; adrenaline administration and aggressive fluid therapy as first-line treatment is responsibility of surgeons and anesthesiologists. Late assessment corresponds to the allergist / clinical immunologist to discern the hypersensitivity mechanism, confirm a diagnosis, and provide prevention setting applicable to each patient. Conclusion: Pediatric perioperative hypersensitivity reactions are rare but with serious consequences. Unlike the adult patient, the latex is the most common agent, therefore, reduction in use becomes a preventive measure.

Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma.

Background Increased outdoor air pollution levels are associated with more frequent use of rescue inhalers in subjects with asthma. However, it is unknown whether this phenomenon is explained by an air pollution-mediated increase in respiratory symptom severity or whether air pollutants decrease the efficacy of short-acting β-agonists (SABAs). Methods We examined the relationship between the percentage change in FEV 1 after SABA use with outdoor air pollution exposure in 85 children with asthma who were 7 to 12 years of age. Outdoor air pollution exposure was determined by measuring nitrogen dioxide (NO 2 ), ozone (O 3 ), and fine particulate matter ( ie , particulate matter with an aerodynamic diameter 2.5 ]) levels. These measurements were obtained from the Mexico City Automated Monitoring Network from network sites located within a 5-km radius of each child's home and school. Results We found that a same-day interquartile increase of 10 parts per billion (ppb) in NO 2 concentration was associated with a reduced response of FEV 1 to SABA therapy (−15%; 95% CI, −29 to −0.5). This association was also significant when considering NO 2 levels in each of the preceding 3 days. An interquartile O 3 increase (16 ppb) in the preceding fifth day was associated with a reduced response to SABA (−11%; 95% CI, −23 to −1); an interquartile PM 2.5 increase (14 μg/m 3 ) was not associated with any significant reductions in the response to SABA therapy. These associations were not observed in children receiving therapy with inhaled corticosteroids. Conclusions Our results suggest that recent exposure to NO 2 and possibly O 3 may reduce the response to SABAs in producing bronchodilation in children with asthma. The association between NO 2 and FEV 1 response to SABA administration may have important implications in understanding how outdoor air pollution levels relate to asthma control.

Asthma and obesity are prevalent disorders, each with a significant impact on the public health. The causality relating obesity and asthma has not been established. The objective of this article is to investigate whether asthma could exacerbate the endothelial activation and to determine the relationship between systemic inflammation and endothelial activation in obese asthmatic children. Eighty-nine children (10-16 years old) were divided according to their diagnosis (asthma, obese nonasthmatic, and obese asthmatic children). Twenty healthy children formed the control group. Three adhesion molecules (E-selectin, sICAM-1, and sVCAM-1) and C-reactive protein (CRP) were measured in serum samples. The levels of sICAM-1 were significantly higher in obese nonasthmatic and obese asthmatic children versus control and lean asthmatic children (414.7+/-154.7, 434.9+/-181.1, 238.6+/-117.8, and 351.2+/-153.5 ng/mL, respectively). No difference was observed between obese nonasthmatic and obese asthmatic groups. No difference of the levels of CRP, E-selectin, and sVCAM-1 was found among the study groups. Correlation analysis showed that E-selectin associated significantly with body mass index (BMI), CRP and the other two adhesion molecules. CRP depended on BMI. sICAM-1 associated with CRP, BMI, and triglycerides. Correlations were verified in multiple regression analysis models in the whole study groups: CRP levels depended on sICAM-1, E-selectin, and sICAM-1 concentrations depended on BMI. Correlations were verified in asthmatic subjects: CRP depended on sICAM-1. These results confirmed the endothelial activation in obese children. Mild nonallergic asthma in our study did not exacerbate the endothelial activation in obese or lean asthmatic children. Significant association between systemic inflammation and endothelial activation was observed in asthmatic children.

BackgroundThe biological mechanisms involved in inflammatory response to air pollution are not clearly understood.ObjectiveIn this study we assessed the association of short-term air pollutant expo...

Objective. A study was conducted to evaluate personal ozone exposure (O 3p ) among asthmatic children residing in Mexico City. Material and Methods. A total of 158 children were recruited from December 1998 to April 2000. On average, three O 3p measurements were obtained per child using passive badges. Time-activity patterns were recorded in a diary. Daily ambient ozone measurements (O 3a ) were obtained from the fixed station, according to children’s residence. Levels of O 3a and ozone, weighted by time spent in different micro-environments (O 3w ), were used as independent variables in order to model O 3p concentrations using a mixed-effects model. Results. Mean O 3p was 7.8 ppb. The main variables in the model were: time spent indoors, distance between residence and fixed station, follow-up group, and two interaction terms (overall R2 =0.50, p

Urticaria is a disease that a fifth of the population shallsuffer once in a lifetime. Recent clinical guidelines have proposed some fundamental changes in the diagnosis and treatment of urticaria, making the development of a national, multidisciplinary guideline, with wide acceptability among different professional groups -both specialists and primary health care workers-, necessary in Mexico.Internationally recognized tools for guidelinedevelopment were used. An interdisciplinary group of clinical experts (some of them knowledgeable in methodology of guideline development) determined the objectives and scope of the Evidence Based Clinical Practice Guideline with SCOPE. It was decided to adapt and transculturize international guidelines on the diagnosis and treatment of urticaria. With AGREE-II three high-quality guidelines (Zuberbier 2014, Sánchez-Borges 2012, Powell 2007) were selected to function as basic guidelines (BG). A set of Clinical Questions was formulated that lead to recommendations/suggestions, based on these BG, taking into account the cultural and economic background of Mexico, according to GRADE recommendation development.By a formal process of discussion and voting during several working-sessions, experts and first level healthcare physicians determined the wording of the final guideline, taking particularly care of developing a document, adjusted to the reality, values and preferences of the Mexican patients. The use of oral second generation, non-sedating antihistamines as first line treatment is emphasized.This document is an Evidence Based Clinical Practice Guideline for the diagnosis and treatment of acute and chronic urticaria, based on three, high quality, international guidelines. It was developed by a multidisciplinary group. Tables and algorithms make the guideline user-friendly for both, first line health care physicians and specialists.Antecedentes: la urticaria es una enfermedad que padece una quinta parte de la población en algún momento de su vida. Las guías internacionales recientes han propuesto unos cambios de fondo en su diagnóstico y tratamiento, por lo que había la necesidad de crear una guía nacional y multidisciplinaria, con base amplia en los gremios de especialistas y médicos de primer contacto en México. Material y método: un grupo interdisciplinario de expertos clínicos y algunos expertos en metodología determinó los objetivos y alcances de la Guía de Práctica Clínica Basada en Evidencia con el instrumento SCOPE. Se decidió llevar a cabo la adaptación y transculturización de guías internacionales para el diagnóstico y tratamiento de urticaria. Con el instrumento AGREE-II se seleccionaron las tres guías de alta calidad, como guías base (Zuberbier 2014, Sánchez-Borges 2012, Powell 2007) para formular y contestar la preguntas clínicas clave, en el contexto cultural y económico mexicano, según el método de desarrollo de recomendaciones GRADE. Resultados: mediante un proceso formal de discusión y votación durante varias juntas de expertos, se terminó la redacción de la forma final de la guía, con especial cuidado de lograr un ajuste a las realidades, valores y preferencias de los pacientes de México. Se hace hincapié en la administración de antihistamínicos vía oral de segunda generación, como tratamiento de primera elección. Conclusión: este documento es una Guía de Práctica Clínica Basada en Evidencia para el diagnóstico y tratamiento de urticaria aguda y crónica, basada en tres guías internacionales de alta calidad. Se desarrolló por un grupo multidisciplinario. Los cuadros y algoritmos hacen a la guía amigable para su uso por médicos de primer contacto y por especialistas.

The International Study of Asthma and Allergy in Childhood (ISAAC) has assessed the prevalence of asthma, as well as the factors related to the disease in different countries. The aim of this study was to identify asthma risks factors in Mexico City. Data were obtained from questionnaires of children participating in a phase 3b ISAAC survey. Two thousand ninety-eight boys and 2008 girls were recruited in the 6- to 7-year-old group and 3243 boy and 3333 girls were recruited in the 13- to 14-year-old group. Logistic regression was used to determine the asthma risks factors. In the logistic regression for cumulative and current asthma prevalence, the variables allergic rhinitis and atopic dermatitis were the most important risk factors with the highest odds ratios (OR > 1.5; p < 0.05). The use of antibiotics and paracetamol in the first 12 months of life were related to cumulative asthma in both genders in the 6- to 7-year-old group. Contact of pregnant mother with farm animals was positively related with cumulative asthma in boys in the 6- to 7-year-old group. The main factors associated with the cumulative and current prevalence of asthma in both age groups were atopic dermatitis and allergic rhinitis. Future interventions for the prevention and early diagnosis and treatment could be focused in the natural history of the atopic march.

Nicotinamide adenine dinucleotide (phosphate) reduced:quinone oxidoreductase (NQO1) and glutathione S-transferase (GST) M1 are phase II enzymes important in response to oxidative stress, such as occurs during exposure to ozone. We examined the relationship between functionally significant polymorphisms in NQO1 (Pro187Ser) and GSTM1 (homozygous deletion) and asthma risk in children with high lifetime exposure to ozone. We enrolled children with asthma from the allergy referral clinic at a public pediatric hospital in Mexico City, together with their parents. We assayed for the Pro187Ser polymorphism in NQO1 using a polymerase chain reaction-restriction fragment length polymorphism assay and for the presence of GSTM1 by polymerase chain reaction among 218 case-parent triads. We did not find strong evidence of an association between NQO1 genotype alone and asthma risk. However, among subjects with homozygous deletion of GSTM1, carriers of a serine allele were at significantly reduced risk of asthma compared with Pro/Pro homozygotes (relative risk = 0.4; 95% confidence interval, 0.2-0.8). The p value for difference in relative risk for NQO1 by GSTM1 genotype = 0.013. These data are consistent with a protective effect of the NQO1 Ser allele in this population of GSTM1-null children with high ozone exposure.

In researching health effects of air pollution, pollutant levels from fixed-site monitors are commonly assigned to the subjects. However, these concentrations may not reflect the exposure these individuals actually experience. A previous study of ozone (O3) exposure and lung function among shoe-cleaners working in central Mexico City used fixed-site measurements from a monitoring station near the outdoor work sites as surrogates for personal exposure. The present study assesses the degree to which these estimates represented individual exposures. In 1996, personal O3 exposures of 39 shoe-cleaners working outdoors were measured using an active integrated personal sampler. Using mixed models, we assessed the relationship between measured personal O3 exposure and ambient O3 measurements from the fixed-site monitoring station. Ambient concentrations were approximately 50 parts per billion higher, on average, than personal exposures. The association between personal and ambient O3 was highly significant (mixed model slope p0.0001). The personal/ambient ratio was not constant, so use of the outdoor monitor would not be appropriate to rank O3 exposure and evaluate health effects between workers. However, the strong within-worker longitudinal association validates previous findings associating day-to-day changes in fixed-site O3 levels with adverse health effects among these shoe-cleaners and suggests fixed-site O3 monitors may adequately estimate exposure for other repeated-measure health studies of outdoor workers.

To evaluate whether acute effects of ozone, nitrogen dioxide, and particulates with mass median diameter less than 10 micro m could be attenuated by antioxidant vitamin supplementation, we conducted a randomized trial using a double-blinded design. Children with asthma (n = 158) who were residents of Mexico City were randomly given a daily supplement of vitamins (50 mg/day of vitamin E and 250 mg/day of vitamin C) or a placebo and were followed from October 1998 to April 2000. Pulmonary function tests were carried out twice a week in the morning. During the follow-up observation period, the mean 1-hour maximum ozone level was 102 ppb (SD = 47), and the mean 24-hour average PM(10) level was 56.7 micro g/m(3) (SD = 27.4). In children with moderate and severe asthma, ozone levels 1 day before spirometry were inversely associated significantly with forced expiratory flow (FEF(25-75)) (-13.32 ml/second/10 ppb; p = 0.000), FEV(1) (-4.59 ml/10 ppb; p = 0.036), and peak expiratory flow (PEF) (-15.01 ml/second/10 ppb; p = 0.04) in the placebo group after adjusting for potential confounding factors. No association between ozone and lung functions was observed in the supplement group. We observed significant differences in lung function decrements between groups for FEF(25-75) and PEF. Our results suggest that supplementation with antioxidants might modulate the impact of ozone exposure on the small airways of children with moderate to severe asthma.

Food allergy is defined as an abnormal immunological reaction to food proteins, which causes an adverse clinical reaction. Most of the people become tolerant to many foods; however some time these tolerances fail and become an immunologic reaction. This is the first clinical expression of allergy, beginning with dermal o gastric manifestations and continues with asthma and rhinitis (the allergy march) and represents a very severe health problem, not only for many children and parents, but also for the entire medical and paramedical community. The evaluation of a child with suspected food allergy includes detailed medical history, physical examination, screening tests and response to elimination diet and to oral food challenge. None of the screening tests, alone or in combination, can definitively diagnose or exclude it. Regarding to the differential diagnosis, the clinician must know the different groups of foods. The treatment includes the exclusion of the involved food and the use of symptomatic medication when it is needed.

Acute asthma is characterized by acute air way obstruction episodes presented as short breath, increased coughing, wheezing and difficult breathing, reversible with bronchodilator. It constitutes one of the most frequent causes of pediatric ER visits whose diagnosis and treatment is not always adequate. It is necessary to carry out a complete medical history searching for the number of previous attacks, risk factors, associated illnesses, triggers, prior hospitalizations, preventive and maintenance treatment used, along with a complete physical examination. During the management of moderate-severe attacks frequent systematic assessments are required to ensure treatment response. In children above 5 years old, monitoring of expiratory peak flow (EPF) during mild-moderate attacks is recommended. In general, a national consensus to classify and treat acute asthma in emergency services does not exist for which the need to develop a clinical practice guide of diagnosis and management arises.

Food allergy or allergic food hypersensitivity is defined as an adverse immunologic reaction caused by immunologic mechanisms mediated or not by IgE. It is a complex disease influenced by polygenetic heritance and environmental factors. Many risk factors have been investigated, pre natal and post natal, and variable and controversial results have been obtained. The most important risk factors associated with food allergy are atopy, lack of breast feeding at least three to six months and early weaning (before four-six months).

Difficult-to-control asthma is a disease that causes serious exacerbations, near-fatal attacks, frequent hospitalizations, and needs chronic use of high doses of inhaled corticosteroids or daily oral corticosteroid therapy. On the basis of epidemiological studies, the risk factors for serious asthma are: female gender, high BMI, sensitivity to aspirin, gastro esophageal reflux, sinusitis, pneumonia history, and beginning of asthma symptoms in adult late age. It has been found that in severe asthma the inflammatory profile commonly changes with major participation of neutrophils, and evidence of destruction and remodelling. The first step in the care of these patients is an evaluation to determine that asthma is the right diagnosis. A systematic and rigorous evaluation helps to asses adequately the differential diagnoses, the comorbilities and the unusual triggers. The aim of the treatment is to achieve the best results with minimum adverse effects. New immunomodulatory therapies are needed for these patients management.

Atopic dermatitis is an inflammatory process characterized by a series of cutaneous alterations of typical morphology and distribution, with intense pruritus of nocturnal predominance, of chronic evolution, stational appearance, and with personal and family history of atopy. On genetically predisposed skin, dry and hypersensitive, the immune factors and other types are implicated in determining the abnormal reactions to multiple endogenous and environmental factors. The diagnosis is clinical, generally obtained by a group of signs and symptoms known as the Hanifin and Rajka criteria. The patients with atopic dermatitis can present with clinical typical manifestations, or minimized and localized variations as well, considered a stigma of atopic constituent. In some patients there can be observed clinical and morphological variations with special localizations denominated atypical variations of atopic dermatitis. The identification of these atypical presentations of atopic dermatitis leads to the differential diagnosis, with an early establishment of the disease's diagnosis and the appropriate and early treatment.

Vaccination is one of the medicine's achievements to control and/or eradicate certain infectious diseases. Vaccines contain antigenic doses derived from microorganisms and/or its toxins, besides they are composed of other substances such as aluminum, gelatin, egg proteins, mercury components (as thimerosal), and antibiotics; therefore, these substances can produce hypersensitivity reactions. The above-mentioned reactions can be evidenced with itch, edema, hives, asthmatic crisis, hypotension and even anaphylactic shock. Due to the importance of vaccination, especially in childhood, it is essential to know the benefits of vaccines, their impact in morbidity and mortality decrease of certain infected-contagious diseases, as well as the adverse effects and the allergic reactions to their application. As immunizations prevent natural infections, they might contribute to a free infectious environment that would allow atopic response. This paper reviews the allergic reactions to vaccines and their influence on the development of atopic disease.

Term anaphylaxis means an immediate hypersensitivity reaction mediated by IgE that produces a clinical syndrome with systemic affection of variable severity. Its prevalence varies according to the habits of each region and of the studied population from 3.2 to 7.6 cases per 100,000 inhabitants per year. Anaphylaxis secondary to the food ingestion accounts for 30-50% of the cases. Some risk factors have been defined, among them the most important are asthma, food allergy and previous reactions to the same food. Biphasic anaphylactic reactions are those presenting a recurrence of anaphylactic symptoms, after the initial remission of them. Success of treatment is based on the early recognition of signs and symptoms and the instauration of treatment with adrenaline.

Allergic conjunctivitis is a group of diseases that are frequent in childhood, associated to several allergic diseases affecting the ocular surface. It is related to type 1 hypersensitivity reactions. Two acute disorders: seasonal allergic conjunctivitis and perennial allergic conjunctivitis, exist, as do three chronic diseases: vernal keratoconjunctivitis, atopic keratoconjunctivitis and giant papillary conjunctivitis. The ocular surface inflammation causes itching, tearing, lid and conjunctival edema-redness, and photophobia during the acute phase and can lead to a classic late-phase response (associated to eosinophilia and neutrophilia) in a subset of individuals. As in the case of several chronic allergic diseases, it can remodel the ocular surface tissue. This allergic disease is very frequent. Vernal keratoconjunctivitis could produce corneal lesions and visual illness; however, atopic keratoconjunctivitis does not permanently affect the vision. The aim of this review is to provide a current overview for a better understanding of the symptoms associated to this disease, to describe its classification, recent advances in its physiopathology and its treatment.

Milk contains more than 40 proteins and all of them may act like human species antigens. The main allergens are beta lactoglobulin, casein, alpha lactoalbumin and seroalbumin; beta lactoglobulin is a protein not existing in human species and is found in maternal milk in minimal quantities (mcg) due to milky products ingested by the mother, these small quantities are responsible of the highest number of sensitizations to this protein. This article reviews the allergy to the cow-milk's protein, also, a critical route to its diagnosis and management is planted.

The International Study of Asthma and Allergies in Childhood (ISAAC) has promoted surveys in asthma and allergic diseases using standardized methodologies including validated questionnaires. Many items in the questionnaires have also been implied in the overweight and obesity etiology.To describe the factors associated with obesity in subjects of 6-7 years and 13-14 years in the ISAAC survey in Mexico City.Data were obtained from questionnaires of children participating in a phase 3b ISAAC survey. Logistic regression was used to determine the obesity risks factors.The factors related to obesity were weekly consumption of meat (+, positive relationship), vegetables, pasta, rice (+) and quartiles of birth weight (+) in boys of 6-7 years. Having suffered eczema at any time, weekly consumption of fruit, pasta, butter, nuts, potato (+), fast food (+), daily TV viewing (+) in girls of 6-7years. Having suffered eczema at any time, weekly consumption of pasta (+), butter, potato, weekly physical exercise in boys of 13-14 years; weekly consumption of pasta, margarine, milk, fast food (+), currently smoking in girls of 13-14 years.There were not common factor patterns for the different groups, birth weight, fast food, TV viewing and lack of exercise have been previously related to pediatric obesity. Asthma was not associated with a higher risk of obesity but medical history of eczema was associated with lower risk of obesity in the 6-7 years girls, and 13-14 years boys. The present study provides the bases for future epidemiological studies and gives some clues on possible public health actions.