Maternal exposure to pyrethroid insecticides during pregnancy and respiratory allergy symptoms among children participating in the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE)

BACKGROUND

Pyrethroid insecticides use for indoor residual spraying (IRS) in malaria-endemic areas results in high levels of exposure to local populations. Pyrethroids may cause asthma and respiratory allergies but no prior study has investigated this question in an IRS area.

METHODS

We measured maternal urinary concentrations of pyrethroid metabolites (cis-DBCA, cis-DCCA, trans-DCCA, 3-PBA) in samples collected at delivery from 751 mothers participating in the Venda Health Examination of Mothers, Babies, and their Environment (VHEMBE), a birth cohort study based in Limpopo, South Africa. At 3.5-year and 5-year follow-up visits, caregivers of 647 and 620 children, respectively, were queried about children's respiratory allergy symptoms based on validated instruments. We applied marginal structural models for repeated outcomes to estimate associations between biomarker concentrations and asthma diagnosis as well as respiratory allergy symptoms at ages 3.5 and 5 years.

RESULTS

We found that a10-fold increase in maternal urinary cis-DCCA, trans-DCCA and 3-PBA concentrations were associated with more than a doubling in the risk of doctor-diagnosed asthma (cis-DCCA: RR = 2.1, 95% CI = 1.3, 3.3; trans-DCCA: RR = 2.1, 95% CI = 1.1, 3.9; 3-PBA: RR = 2.4, 95% CI = 1.0, 5.8) and an about 80% increase in the risk of wheezing or whistling in the chest (cis-DCCA: RR = 1.8, 95% CI = 1.1, 3.0; trans-DCCA: RR = 1.7, 95% CI = 1.1, 2.6; 3-PBA: RR = 1.8, 95% CI = 1.0, 3.3) and suspected asthma (cis-DCCA: RR = 1.8, 95% CI = 1.1, 3.1; trans-DCCA: RR = 1.8, 95% CI = 1.1, 2.8). We also observed that higher concentrations of cis-DBCA and 3-PBA were related to increases in the risks of dry cough at night (RR = 3.5, 95% CI = 1.3, 9.5) and seasonal rhinoconjunctivitis (RR = 2.0, 95% CI = 1.1, 3.9), respectively.

CONCLUSION

Maternal exposure to pyrethroids may increase the risk of asthma and other respiratory allergy symptoms among preschool children from an IRS area.

Do nasal and nasopharyngeal obstruction and their medical-surgical deobstruction significantly influence facial divergence? A concise review of major clinical studies with meta-analysis

Introduction

The term « adenoid facies » suggests a causal relationship between nasopharyngeal obstruction and facial hyperdivergence in growing subjects. The strength of this association is controversial and few « quantified » values exist.

Materials and methods

A rapid electronic search was conducted on PubMed and Embase to find the main cephalometric studies involving patients with nasal/nasopharyngeal obstruction compared to a control sample. A meta-analysis was carried out to quantify the effect of obstruction (1) and intervention to relieve the obstruction (2) on mandibular divergence (SN/Pmand angle), maxillo-mandibular divergence (PP/Pmand angle), inclination of the occlusal plane (SN/Poccl) and the gonial angle (ArGoMe).

Results

Qualitatively, the studies' bias level ranged from moderate to high. Results were concordant about the significant effect of the obstruction on facial divergence (1) with an increase in SN/Pmand (+3.6° on average, +4.1° in children <6 years), PP/Pmand (+5.4° on average, +7.7° <6 years), ArGoMe (+3.3°) and SN/Pocc (+1.9°). Surgical interventions to remove the respiratory obstacle in children (2) generally did not normalize the direction of growth, with the exception, with a very low level of evidence, of adenoidectomies/adeno-tonsillectomies, performed at an age less than 6-8 years.

Conclusion

Early detection of respiratory obstacles and postural abnormalities associated with oral breathing appears to be decisive in order to hope for management at a young age and normalization of the direction of growth. However, the effects on mandibular divergence remain limited, requiring caution, and cannot be considered a surgical indication.

The intriguing possibility of using probiotics in allergen-specific immunotherapy

Allergen immunotherapy (AIT) can be considered the etiological therapy for allergic rhinitis and hymenoptera venom allergy. Its role is increasingly emerging in the context of IgE mediated food allergy, where the achievement of tolerance, or the permanent resolution of an allergy, represents the optimal goal of AIT. AIT treatment, indicated in adults and children with allergic rhinitis, has a preventative effect on the development of asthma and can also be used when asthma is associated to rhinitis; however, it is not the first choice for treatment of isolated asthma. While knowledge on immunological mechanisms, efficacy, and safety of AIT is known, an intriguing line of investigation has arisen on how the action of AIT is modulated by the use of probiotics, starting from awareness that the microbiome is altered in allergic conditions: the use of probiotics in inducing the stimulation of innate immunity via toll-like receptor activation, thus acting as adjuvants in AIT, is hereby examined. Therefore, by analyzing literature on AIT and probiotics, we intend to draw attention to how the role and use of AIT are emerging as being increasingly important for both the short- and long-term management of allergic diseases and how recourse probiotics may represent an additional therapeutic strategy to modulate the effectiveness of AIT. However, further investigations are needed to better identify which probiotics to use, the dosage, and the optimal duration to obtain correct immunomodulation, and how to best customize their use, including a "AIT + probiotics" strategy in the field of precision medicine.

Differential Quercus spp. pollen-particulate matter interaction is dependent on geographical areas

Particulate matter (PM) and pollen interaction, either airborne or at the respiratory mucosa needs further clarification, as allergic reaction intensification can be related to the PM physical characteristics and toxicity. This study aimed to investigate the physical-chemical properties of PM that can adhere to the pollen wall during its transport or inhalation, using Quercus spp. as a model, in three Portuguese cities with different geographical locations, meteorological influence and urbanization levels. Possible sources were evaluated through air masses trajectory analysis using the HYSPLIT model and correlation with meteorological factors. The sampling was performed using a 7-days Hirst-type volumetric sampler, and the pollen grains were observed using a Field Emission Electron Probe Microanalyser for PM analysis. A secondary electron image of each pollen grain was taken, to determine the adhered particles characteristics and energy dispersive x-ray spectroscopy (EDS) spectra were obtained for individual particles. A total of 484 pollen grains was observed, with 7683 particles counted and 1914 EDS spectra analyzed. The particle's equivalent diameter ranged from 0.3-16 μm, with most having a diameter < 3 μm. For the three cities, there were significant differences in the number of particles per pollen and the % area occupied by the particles. Particles adhered were mainly Si-rich, but variations in other dominant groups were observed. For Évora and Guarda, Ca-rich, SO-rich were second and third more representative, while Porto were Organic and Cl-rich. Metals&Oxides were found in all cities with the highest number in Porto. P-rich particles were only found in Évora. Sea salt particles were observed in Évora, coincide with air mass trajectories possible carrying them from the Mediterranean Sea. In conclusion, the PM physical characteristics are similar between the studied cities, however, the dominant chemical composition is different, certainly impacting the exposome influence and pollen-allergy intensification towards the same pollen type and concentration.

Allergens Prevalence among Patients with Respiratory Allergies in Mashhad, Iran

BACKGROUND

Respiratory allergies are among the most common allergies in the world with an increasing number of people affected in recent decades. Determination of allergens prevalence in each area is considered as the first step in prevention of allergic diseases and developing novel and more effective immunotherapies. The aim of this study was to determine the prevalence of the most common allergens among patients with respiratory allergies in Mashhad, Iran.

MATERIALS AND METHODS

This cross sectional study included 1246 people who were referred to Allergy Clinic of Mashhad University of Medical Sciences with respiratory allergic symptoms from 2012 to 2017 in which a questionnaire containing demographic information was completed and Skin Prick Test was performed for each patient.

RESULTS

Among 1246 patients with respiratory symptoms, there were 1084 patients with allergic rhinitis (87%), 69 patients with allergic asthma (5.5%), 14 patients with allergic rhinoconjunctivitis (1.1%) and 79 patients with both allergic rhinitis and asthma (6.3%) with an overall male to female ratio of 1.18. Rhinorrhea (86.3%), sneezing (81.1%) and itchy eyes (68.4%) were the most common symptoms in patients with respiratory allergic disorders in this study and the highest rate of sensitivity was to pollens including Salsola kali (82.3%), pigweed mix (65.1%), tree mix (51.7%) and ash (49.8%), respectively.

CONCLUSION

Generally, Salsola kali seems to be the main allergen in different respiratory allergies including allergic rhinitis, asthma and rhinoconjunctivitis in semi-arid climate of Mashhad, Iran.

Collaboration between specialties for respiratory allergies in the International Classification of Diseases (ICD)-11

Background

The International Classification of Diseases (ICD) has been grouping the allergic and hypersensitivity disorders involving the respiratory tract under topographic distribution, regardless of the underlying mechanisms, triggers or concepts currently in use for allergic and hypersensitivity conditions. In order to strengthen awareness and deliberate the creation of the new “Allergic or hypersensitivity disorders involving the respiratory tract” section of the ICD-11, we here propose make the building process public.

Methods

The new frame has been constructed to cover the gaps previously identified and was based on consensus academic reports and ICD-11 principles. Constant and bilateral discussion was kept with relevant groups representing specialties and resulted in proposals submission into the ICD-11 online platform.

Results

The “Allergic or hypersensitivity disorders involving the respiratory tract” section covers 64 entities distributed across five main categories. All the 79 proposals submitted resulted from an intensive collaboration of the Allergy working group, relevant Expert working groups and the WHO ICD governance.

Conclusion

The establishment of the ICD-11 “Allergic or hypersensitivity disorders involving the respiratory tract” section will allow the dissemination of the updated concepts to be used in clinical practice by many different specialties and health professionals.

Characterisation of particulate matter on airborne pollen grains

A characterization of the physical-chemical composition of the atmospheric PM adsorbed to airborne pollen was performed. Airborne pollen was sampled using a Hirst-type volumetric spore sampler and observed using a Field Emission Electron Probe Microanalyser for PM analysis. A secondary electron image was taken of each pollen grain and EDS spectra were obtained for individually adsorbed particles. All images were analysed and the size parameters of the particles adsorbed to pollen was determined. The measured particles' equivalent diameter varied between 0.1 and 25.8 μm, mostly in the fine fraction. The dominant particulates identified were Si-rich, Organic-rich, SO-rich, Metals & Oxides and Cl-rich. Significant daily differences were observed in the physical-chemical characteristics of particles adsorbed to the airborne pollen wall. These differences were correlated with weather parameters and atmospheric PM concentration. Airborne pollen has the ability to adsorb fine particles that may enhance its allergenicity.

[Correlation between the magnitude of skin prick test reactivity and pollen-specific serum IgE levels in patients with respiratory allergy]

BACKGROUND

For the etiological diagnosis of allergic respiratory diseases skin tests or specific serum IgE determination are used.

OBJECTIVE

To determine the correlation between the extent of reactivity to cutaneous prick tests and the levels of pollen specific serum IgE in patients with respiratory allergy.

PATIENTS AND METHODS

A prolective, descriptive and transversal study was done with patients of both genders, aged 2 to 60 years, who attended for the first time at the service of Allergy and Clinical Immunology of University Hospital of Puebla, Mexico, with presumptive diagnosis of respiratory allergy. All patients underwent clinical history, skin prick tests with standardized allergenic extracts and quantification of pollen specific serum IgE by chemiluminescence method. We estimated the correlation index r using the statistical method Pearson product-moment correlation coefficient; a value r equal to or higher than 0.70 was considered a significant relationship or a high correlation.

RESULTS

Nine-one patients were included, of whom 58.2% were female. The diagnoses were: allergic rhinitis (79.1%), asthma and allergic rhinitis (16.5%) and only asthma (4.4%). Only significant correlation was found in patients with allergic rhinitis for Rumex crispus (r = 0.702) and in patients with asthma and rhinitis for Ambrosia trifida (r = 1).

CONCLUSION

Only for Rumex crispus and Ambrosia trifida, the skin prick tests or the determination of specific serum IgE levels are comparable diagnostic methods of allergic respiratory diseases.

[Tropical endemic limbo-conjunctivitis (TELC) and allergic management: a preliminary study in Togolese children]

PURPOSE

To study the impact of certain allergens on the manifestations of tropical endemic limbo-conjunctivitis (TELC) in Togolese children.

METHODS

This is a 3-year prospective study of 36 Togolese children with acute recurrences of TELC after 1 to 5 months of remission. Skin prick tests were conducted with five perennial respiratory allergens (dust mites, paper mites, roaches, dog and cat, grass pollen) and three food allergens (egg, peanut, shrimp). The reactions were compared to a negative control (saline solution) and a positive control (histamine or codeine sulfate). Length of remissions between acute exacerbations before and after allergy testing were noted.

RESULTS

Thirty-five children were polysensitive. Individual allergens were: dust mites (83.3%), followed by cockroach (72.2%), shrimp (61.1%), peanuts (55.6%), eggs (44.4%), the cat and/or dog dander (38.9%), and grass pollen (22.2%). The rate of remission prior to allergy testing was 77.8% within 2 months after treatment of an exacerbation; with allergy management, 55.5% of patients experienced remission beyond 1 year.

DISCUSSION

The literature reports that TELC is caused by multiple antigens. The clear predominance of respiratory and food allergens may lead to a new pathway for managing TELC in Togolese children.

CONCLUSION

Allergy testing is of great importance for patients with frequent acute exacerbations of TELC.