Asthma, rhinitis, and atopic dermatitis (AD) are interrelated clinical phenotypes that partly overlap in the human interactome. The concept of “one‐airway‐one‐disease,” coined over 20 years ago, is a simplistic approach of the links between upper‐ and lower‐airway allergic diseases. With new data, it is time to reassess the concept. This article reviews (i) the clinical observations that led to Allergic Rhinitis and its Impact on Asthma (ARIA), (ii) new insights into polysensitization and multimorbidity, (iii) advances in mHealth for novel phenotype definitions, (iv) confirmation in canonical epidemiologic studies, (v) genomic findings, (vi) treatment approaches, and (vii) novel concepts on the onset of rhinitis and multimorbidity. One recent concept, bringing together upper‐ and lower‐airway allergic diseases with skin, gut, and neuropsychiatric multimorbidities, is the “Epithelial Barrier Hypothesis.” This review determined that the “one‐airway‐one‐disease” concept does not always hold true and that several phenotypes of disease can be defined. These phenotypes include an extreme “allergic” (asthma) phenotype combining asthma, rhinitis, and conjunctivitis. Rhinitis alone and rhinitis and asthma multimorbidity represent two distinct diseases with the following differences: (i) genomic and transcriptomic background (Toll‐Like Receptors and IL‐17 for rhinitis alone as a local disease; IL‐33 and IL‐5 for allergic and non‐allergic multimorbidity as a systemic disease), (ii) allergen sensitization patterns (mono‐ or pauci‐sensitization versus polysensitization), (iii) severity of symptoms, and (iv) treatment response. In conclusion, rhinitis alone (local disease) and rhinitis with asthma multimorbidity (systemic disease) should be considered as two distinct diseases, possibly modulated by the microbiome, and may be a model for understanding the epidemics of chronic and autoimmune diseases.

Vitamin D deficiency (VDD) in pregnant women and their children is an important health problem with severe consequences for the health of both. Thus, the objectives of this review were to reassess the magnitude and consequences of VDD during pregnancy, lactation and infancy, associated risk factors, prevention methods, and to explore epigenetic mechanisms in early fetal life capable of explaining many of the non-skeletal benefits of vitamin D (ViD). Original and review articles, and consensus documents with elevated level of evidence for VDD-related clinical decisions on the health of pregnant women and their children, as well as articles on the influence of ViD on epigenetic mechanisms of fetal programming of chronic diseases in adulthood were selected among articles published on PubMed over the last 20 years, using the search term VitD status, in combination with Pregnancy, Offspring health, Child outcomes, and Programming. The following items were analyzed: ViD physiology and metabolism, risk factors for VDD and implications in pregnancy, lactation and infancy, concentration cutoff to define VDD, the variability of methods for VDD detection, recommendations on ViD replacement in pregnant women, the newborn and the child, and the epigenetic influence of ViD. VDD is a common condition among high-risk pregnant women and their children. The routine monitoring of serum 25(OH)D3 levels in antenatal period is mandatory. Early preventive measures should be taken at the slightest suspicion of VDD in pregnant women, to reduce morbidity during pregnancy and lactation, as well as its subsequent impact on the fetus, the newborn and the child.

In late 2019, a new infectious disease (COVID-19) was identified in Wuhan, China, which has now turned into a global pandemic. Countries around the world have implemented some type of blockade to lessen their infection and mitigate it. The blockade due to COVID-19 has drastic effects on the social and economic fronts. However, recent data released by the National Aeronautics and Space Administration (NASA), European Space Agency (ESA), Copernicus Sentinel-5P Tropomi Instrument and Center for Research on Energy and Clean Air (CREA) indicate that the pollution in some of the epicenters of COVID-19, such as Wuhan, Italy, Spain, USA, and Brazil, reduced by up to 30%. This study compiled the environmental data released by these centers and discussed the impact of the COVID-19 pandemic on environmental pollution.

To analyze the impacts of climate change on the development of immature respiratory and immune systems in children. The authors of the present study performed a non-systematic review of English, Spanish, and Portuguese articles published in the last five years in databases such as PubMed, EMBASE, and SciELO. The terms used were air pollution OR climate changes OR smoke, AND children OR health. The increase in the prevalence of some diseases, such as allergic ones, is attributed to the interactions between genetic potential and the environment. However, disordered growth combined with inadequate waste management has caused problems for the planet, such as heatwaves, droughts, forest fires, increased storms and floods, interference in food crops and their nutritional values, changes in the infectious disease pattern, and air pollution resulting from the continuous use of fossil fuels. Children, beings still in the development stage with immature respiratory and immune systems, are the primary victims of the climate crisis. The authors documented that prenatal and postnatal exposure to ambient air pollutants will accelerate or worsen the morbidity and mortality of many health conditions, including allergic diseases. Ambient air pollutants change the microbiota, interfere with the immune response, and take direct action on the skin and respiratory epithelium, which facilitates the penetration of allergens. Understanding how the children and adolescent health and well-being are affected by climate change is an urgent matter.

Despite anti-smoking prevention programs, many adolescents start smoking at school age. The main objectives of this study were to determine the prevalence and risk factors associated with smoking in adolescents living in Uruguaiana, RS, Brazil. A prospective study was conducted in adolescents (12-19 years), enrolled in municipal schools, who answered a self-administered questionnaire on smoking. 798 adolescents were enrolled in the study, with equal distribution between genders. The tobacco experimentation frequency (ever tried a cigarette, even one or two puffs) was 29.3%; 14.5% started smoking before 12 years of age and 13.0% reported smoking at least one cigarette/day last month. Having a smoking friend (OR: 5.67, 95% CI: 2.06-7.09), having cigarettes offered by friends (OR: 4.21, 95% CI: 2.46-5.76) and having easy access to cigarettes (OR: 3.82, 95% CI: 1.22-5.41) was identified as factors associated with smoking. Having parental guidance on smoking (OR: 0.67, 95% CI: 0.45-0.77), having no contact with cigarettes at home in the last week (OR: 0.51, 95% CI: 0.11-0.79) and knowing about the dangers of electronic cigarettes (OR: 0.88, 95% CI: 0.21-0.92) were identified as protection factors. The prevalence of smoking among adolescents in Uruguaiana is high. The implementation of measures to reduce/stop tobacco use and its new forms of consumption, such as electronic cigarettes and hookah, are urgent and imperative in schools.

The study aimed to conduct a systematic review of the literature to verify the association between exposure to pesticides and allergic diseases (asthma, allergic rhinitis, and atopic dermatitis) in children and adolescents. A systematic review and meta-analysis were performed using the PRISMA method with the question “What is the association between exposure to pesticides and allergic diseases in children (asthma, allergic rhinitis, and atopic dermatitis)?” MEDLINE, EMBASE, SciELO, and Cochrane electronic databases were searched throughout the period in the literature up to September 2020. A total of 1296 studies were found, and 24 were selected. Exposure to pesticides showed a two-fold greater risk of developing or exacerbating asthma in children and adolescents (odds ratio [OR] = 2.14 95% confidence interval [CI] 1.26-3.64, p < 0.01). There was no association between exposure to pesticides and the development of allergic rhinitis (OR = 2.73, 95% CI 0.13-57.8, p = 0.52) and atopic dermatitis (OR = 2.19, 95% CI 0.51-9.36, p = 0.29). Exposure to pesticides increases the risk of developing or exacerbating asthma in children and adolescents. There was no evidence of an association between exposure to pesticides and the development of allergic rhinitis and atopic dermatitis in children and adolescents, possibly due to the low number of studies found in this review.