Seasonal Allergens Research Articles

Allergic Rhinitis, Conjunctivitis, and Sinusitis

Allergic rhinitis is an IgE-mediated inflammatory response in the nose to foreign substances known as allergens. It can be classified as seasonal or perennial, depending on the allergens triggering the reaction. This characterization is good for identifying allergen triggers but is limited because it is based on the duration of outdoor exposure (e.g., grass pollinates for 2 months in Chicago and nearly 11 months in Texas). Also, some perennial allergens, such as dust mites, have seasons. The Allergic Rhinitis in Asthma (ARIA) classification was developed to focus on therapy. It assumes that exposure to perennial and to seasonal allergen leads to the same immunologic response. ARIA places patients into the categories of mild intermittent, mild persistent, moderate/severe intermittent, and moderate/severe persistent to recommend treatment and emphasizes the link between allergic rhinitis and asthma.1 This review contains 5 figures, 12 tables, and 59 references. Key Words: Sinusitis, infection, allergy, antibiotic, decongestant, antihistamine

Allergen-specific immunotherapy induces the suppressive secretoglobin 1A1 in cells of the lower airways.

While several systemic immunomodulatory effects of allergen-specific immunotherapy (AIT) have been discovered, local anti-inflammatory mechanisms in the respiratory tract are largely unknown. We sought to elucidate local and epithelial mechanisms underlying allergen-specific immunotherapy in a genome-wide approach. We induced sputum in hay fever patients and healthy controls during the pollen peak season and stratified patients by effective allergen immunotherapy or as untreated. Sputum was directly processed after induction and subjected to whole transcriptome RNA microarray analysis. Nasal secretions were analyzed for Secretoglobin1A1 (SCGB1A1) and IL-24 protein levels in an additional validation cohort at three defined time points during the 3-year course of AIT. Subsequently, RNA was extracted and subjected to an array-based whole transcriptome analysis. Allergen-specific immunotherapy inhibited pro-inflammatory CXCL8, IL24, and CCL26mRNA expression, while SCGB1A1, IL7, CCL5, CCL23, and WNT5BmRNAs were induced independently of the asthma status and allergen season. In our validation cohort, local increase of SCGB1A1 occurred concomitantly with the reduction of local IL-24 in upper airways during the course of AIT. Additionally, SCGB1A1 was identified as a suppressor of epithelial gene expression. Allergen-specific immunotherapy induces a yet unknown local gene expression footprint in the lower airways that on one hand appears to be a result of multiple regulatory pathways and on the other hand reveals SCGB1A1 as novel anti-inflammatory mediator of long-term allergen-specific therapeutic intervention in the local environment.

Evaluation of House Dust Mite Dose Response in the Environmental Exposure Unit

As a controlled allergen challenge facility, the Environmental Exposure Unit (EEU) is a valuable model to investigate allergic rhinitis (AR). While seasonal allergens have been previously studied in the EEU, here we sought to evaluate the clinical manifestations of house dust mite (HDM)-induced AR in the HDM-EEU.

Sensitization to house dust mite allergens might be related to the low sensitivity of ImmunoCAP to pollen allergen.

Skin prick test (SPT) and ImmunoCAP are widely used to diagnose allergies. However, previous studies showed discordance between the results of SPT and ImmunoCAP and there remains a lack of research to better understand the differences in results between the two tests. We investigated factors that affected the discordance between SPT and ImmunoCAP results. We reviewed the medical records of 94 subjects who underwent both SPT and ImmunoCAP for six allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, alder, ragweed, mugwort, and Humulus japonicus). We retrospectively analyzed whether age, sex, body mass index, and allergic sensitization to house dust mite (HDM) or seasonal allergens affected the discordance of results between SPT and ImmunoCAP. The positivity rates for HDM allergens were similar between the two tests. For seasonal allergens, however, the positivity rates were much higher in the SPT than those in the ImmunoCAP. The concordance rates of the two tests were relatively higher for HDM than seasonal allergens. Moreover, the ratio of the subjects positive by SPT and negative by ImmunoCAP was higher for seasonal allergens. Positivity for HDM allergens by SPT resulted in a higher rate of mismatch between the two tests for seasonal allergens. The ImmunoCAP test for seasonal antigens showed low positivity rates compared to SPT in cases positive for HDM allergens. This suggests that the results of ImmunoCAP are less sensitive for seasonal allergens compared to the SPT in cases positive for HDM allergens.

Seasonal Variation in miR-328-3p and let-7d-3p Are Associated With Seasonal Allergies and Asthma Symptoms in Children.

ObjectiveMicroRNAs (miRs) are small non-coding RNA molecules of around 18–22 nucleotides that are key regulators of many biologic processes, particularly inflammation. The purpose of this study was to determine the association of circulating miRs from asthmatic children with seasonal variation in allergic inflammation and asthma symptoms.MethodsWe used available small RNA sequencing on blood serum from 398 children with mild-to-moderate asthma from the Childhood Asthma Management Program. We used seasonal asthma symptom data at the study baseline and allergen affection status from baseline skin prick tests as primary outcomes. We identified differentially expressed (DE) miRs between pairs of seasons using DESeq2. Regression analysis was used to identify associations between allergy status to specific seasonal allergens and DE miRs in 4 seasons and between seasonal asthma symptom data and DE miRs. We performed pathway enrichment analysis for target genes of the DE miRs using DAVID.ResultsAfter quality control, 398 samples underwent differential analysis between the 4 seasons. We found 52 unique miRs from a total of 81 DE miRs across seasons. Further investigation of the association between these miRs and sensitization to seasonal allergens using skin prick tests revealed that 26 unique miRs from a total of 38 miRs were significantly associated with a same-season allergen. Comparison between seasonal asthma symptom data revealed that 2 of these 26 miRs also had significant associations with asthma symptoms in the same seasons: miR-328-3p (P < 0.03) and let-7d-3p (P < 0.05). Enrichment analysis showed that the most enriched pathway clusters were Rap1, Ras, and MAPK signaling pathways.ConclusionOur results show seasonal variation in miR-328-3p and let-7d-3p are significantly associated with seasonal asthma symptoms and seasonal allergies. These indicate a potentially protective role for let-7d-3p and a deleterious role for miR-328-3p in asthmatics sensitized to mulberry. Further work will determine whether these miRs are drivers or results of the allergic response.

A072 HOUSE DUST MITE ENVIRONMENTAL EXPOSURE UNIT: CLINICAL VALIDATION OF A MODEL FOR PERENNIAL ALLERGIC RHINITIS

Allergic rhinitis (AR) is an inflammatory disease of the nasal mucosa that manifests as rhinorrhea, nasal congestion, and sneezing. Induced by seasonal (eg: pollens) or perennial (eg: house dust mite; HDM) allergens, AR can be successfully studied using the Environmental Exposure Unit (EEU), a clinical model which has been previously validated for birch, ragweed, and grass pollens. In this study, we seek to clinically validate the HDM-EEU for HDM-induced AR.

Multimorbidity in asthma, association with allergy, inflammatory markers and symptom burden, results from the Swedish GA2 LEN study.

BackgroundAsthma is common worldwide and a large part of subjects with asthma have concomitant allergic multimorbidity in the form of rhinitis and/or eczema.ObjectiveThe aim of this study is to investigate whether the presence of allergic multimorbidity in asthma relates to allergic sensitization, allergic and respiratory symptoms, quality of life, inflammatory markers, lung function, use of medication and background factors.MethodsA total of 437 asthmatics from the (GA2LEN) cross‐sectional survey in Sweden were grouped depending on the presence of rhinitis and/or eczema. The impact of allergic multimorbidity was assessed in terms of allergic sensitization, allergic and respiratory symptoms, quality of life, type‐2 inflammatory markers (exhaled nitric oxide, eosinophil activation markers, periostin), lung function, use of medication and background factors.ResultsSubjects with asthma, rhinitis and eczema were more likely to be sensitized to seasonal allergens (67% vs 32%, P < .001), food allergens (54% vs 18%, P < .001) and to have a higher degree of sensitization than subjects with only asthma (23% vs 10%, P < .001). Subjects with allergic multimorbidity more often had allergic reactions to food (28% vs 10%, P = .002), more respiratory symptoms and anxiety/depression (40% vs, 14%, P < .001) than subjects with only asthma, despite having similar levels of type 2 inflammatory markers. Individuals with allergic multimorbidity were more likely to be diagnosed with asthma before the age of 12 (48% vs 27%, P = .016) and to have maternal heredity for allergy (53% vs 33%, P = .011) than subjects with only asthma.Conclusion and clinical relevanceAsthmatics with allergic multimorbidity are more likely to be sensitized to seasonal aeroallergens, food allergens and they have a higher degree of sensitization compared with those with only asthma. Allergic multimorbidity is associated with respiratory and allergy symptoms, anxiety and/or depression.

Reduction of allergic rhinitis symptoms with face mask usage during the COVID-19 pandemic

Reduction of allergic rhinitis symptoms with face mask usage during the COVID-19 pandemic

Initial effects of the COVID-19 pandemic on pediatric asthma emergency department utilization

Spring in the Northeastern United States usually represents a period of relatively high emergency department (ED) utilization for childhood asthma. Putative drivers of this phenomenon include seasonal allergens and the tail of winter respiratory viruses. The emergence and spread of the novel severe acute respiratory syndrome coronavirus 2 infection in the United States coincided with spring in the Northeastern United States, and many national and international health organizations, including the Centers for Disease Control and Prevention, were concerned that asthma would be a risk factor for worse outcomes.

Serum immunoglobulin E reactivity to cross-reacting panallergen components in north-eastern Poland patients pollen sensitized

Background: The presence of immunoglobulin E (IgE), which cross-reacts with allergen components, such as profilins, polcalcins, and cross-reacting carbohydrate determinants (CCD), creates a problem when selecting patients for allergen immunotherapy by using conventional methods. The aim of this study was to evaluate the prevalence of sensitization to profilins, polcalcins, and CCDs in patients with seasonal pollen allergic rhinitis. Methods: The study was performed on a group of 112 patients with seasonal pollen allergic rhinitis, ages 14 to 55 years, with sensitization to at least one seasonal allergen (IgE > 0.7 kUA/L). The presence of IgE sensitization to recombinant (r) Bet v 2, rPhl p 12, rBet v 4, rPhl p 7, and CCDs, in addition to rBet v 1, rPhl p 1, rPhl p 5, was evaluated by using a multiparameter immunoblot. Results: Among the studied patients, 64.3, 80.4, and 41.1% were sensitized to birch, timothy grass, and mugwort pollen, respectively. Sensitization to profilins rBet v 2/Phl p 12 was demonstrated in 28.6%, to polcalcins Bet v 4/Phl p 7 in 8.9%, and to CCDs in 25%. In 29.3%, serum IgE reactivity to any of the cross-reactive components could be demonstrated. Serum IgE reactivity to rBet v 2 was always accompanied by IgE reactivity to rPhl p 12, and IgE reactivity to rBet v 4 was always accompanied by IgE reactivity to rPhl p 7. Among the patients with pollinosis co-sensitized to at least two allergen sources according to extract-based diagnosis, possible false-positive results due to sensitization to cross-reactive components were detected in 17.9%. Conclusion: Evaluation of sensitization to cross-reacting components may be useful in evaluation of patients with pollen allergy who are being assessed for allergen immunotherapy to optimize the constitution of their immunotherapy vaccines.

Study of atopic multimorbidity in subjects with rhinitis using multiplex allergen component analysis

BackgroundRhinitis is a common problem within the population. Many subjects with rhinitis also have atopic multimorbidity, such as asthma and eczema. The purpose of this investigation was to compare subjects with only rhinitis to those that have rhinitis, asthma and/or eczema in relation to immunoglobulin E (IgE) sensitization, inflammatory markers, family history, lung function and body mass index (BMI).MethodsA total of 216 adult subjects with rhinitis from the European Community Respiratory Health Survey II were investigated with multiplex component allergen analysis (103 allergen components), total IgE, C-reactive protein, eosinophilic cationic protein, fractional exhaled nitric oxide and spirometry. Rhinitis, eczema, asthma and parental allergy were questionnaire-assessed.ResultsOf the 216 participants with rhinitis, 89 also had asthma and/or eczema. Participants with rhinitis that also had asthma or eczema were more likely to be IgE-sensitized (3.44, odds ratio, OR: 95% CI 1.62–7.30, adjusted for sex, age, mother’s allergy, total IgE and forced expiratory volume (FEV1)). The number of IgE-positive components was independently associated with atopic multimorbidity (1.11, OR: 95% Cl 1.01–1.21) adjusted for sex, age, mother’s allergy, total IgE and FEV1. When analysing different types of sensitization, the strongest association with atopic multimorbidity was found in participants that were IgE-sensitized both to perennial and seasonal allergens (4.50, OR: 95% CI 1.61–12.5). Maternal allergy (2.75, OR: 95% CI 1.15–4.46), high total IgE (2.38, OR: 95% CI 1.21–4.67) and lower FEV1 (0.73, OR: 95% CI 0.58–0.93) were also independently associated with atopic multimorbidity, while no association was found with any of the other inflammatory markers.ConclusionIgE polysensitization, to perennial and seasonal allergens, and levels of total IgE seem to be the main determinants of atopic multimorbidity in subjects with rhinitis. This indicates that disease-modifying treatment that targets IgE sensitization may be of value when decreasing the risk of developing atopic multimorbidity.

Patient and physician perceptions of seasonal allergic rhinitis and allergen immunotherapy: a parallel physician patient survey

BackgroundThe Allergy Patient Identification for Immunotherapy (AsPIRe) program was a parallel physician and patient survey. The objectives were to examine physician and patient perceptions of seasonal allergy symptoms and their impact on patients, and to examine patient and physician attitudes to allergen immunotherapy (AIT) for seasonal allergies. AsPIRe was led by a steering committee and received research ethics board clearance from Queen’s University.MethodsAllergists (17) from across Canada enrolled in the AsPIRe program and completed an on-line survey to collect demographic information and baseline perceptions. Allergists then recruited patients and completed paper-based parallel physician and patient questionnaires. Patients received an AIT informational booklet with their questionnaire. Patients who were AIT-naïve with no contraindication to AIT and 12 years of age and older met the inclusion criteria.ResultsThe survey was in field from February 2018 to June 2018. A total of 141 allergist surveys and 136 patient surveys were completed. Mean age of patients was 30 years old (range 12–70). Fifty-seven percent of patients reported prior knowledge of AIT. Seventy-two percent of patients reported seasonal allergies of longer than 5 years duration and in this subset of patients, 46% were at their first allergist visit. Seventy-three percent of all patients indicated they would be likely or very likely to try sublingual immunotherapy (SLIT), if recommended by their allergist compared to 36% for subcutaneous immunotherapy (SCIT). Conversely, 10% of patients reported they would be unlikely or very unlikely to try SLIT compared to 46% of patients who would be unlikely or very unlikely to try SCIT if recommended by their allergist.ConclusionsIn this particular study cohort, there was a gap in perception between allergists and their patients as to the impact of allergy symptoms on daily life. Patients reported being more frequently impacted vs. their physician’s assessment. When asked about preference for AIT options, Canadian patients reported they were more likely to follow their allergists’ recommendation for initiation of SLIT compared to SCIT.

Coexistence of nasal reactivity to allergens with and without IgE sensitization in patients with allergic rhinitis.

Allergic rhinitis (AR) and local allergic rhinitis (LAR) are defined by nasal reactivity to aeroallergens with and without positive skin prick test (SPT), respectively. In this study, we aimed to investigate whether both types of allergen-specific reactivity can coexist in the same individual. Forty-eight patients with perennial rhinitis symptoms and positive SPT with seasonal allergens only (discrepant group) were subjected to consecutive nasal allergen challenges (NAC) with seasonal (NAC-S) and perennial allergens (NAC-P). A nasal lavage was collected before and after the NACs to measure eosinophil cationic protein (ECP). A basophil activation test (BAT) with seasonal and/or perennial allergens was performed in ten patients from the discrepant group and in six seasonal allergic rhinitis (SAR), eight perennial local allergic rhinitis (LAR), six nonallergic rhinitis (NAR), and six healthy control (HC) individuals. All patients in the discrepant group tested positive in the NAC-S, and 41 of them (85.4%), also in the NAC-P (group A). Conversely, seven patients tested negative in the NAC-P (group B). ECP in the nasal lavage increased after the NAC-P in the group A (P=.004), but not in the group B. The BAT with seasonal allergens was positive in 100% of SAR and group A cases, whereas the BAT with perennial allergens was positive in 37.5% and 60% of LAR and group A cases, respectively. All NAR and HC subjects tested negative for the BAT. This study shows that nasal reactivity to aeroallergens with and without positive SPT can coexist in the same patient. We propose the term dual allergic rhinitis for this rhinitis phenotype.

Clinical utility of diagnostic methods in respiratory allergy in pediatric patients.

Respiratory allergy is a single condition which affects upper and lower airways. The diagnose in childhood is essential to prevent the allergy respiratory progression. We aimed to analyze the clinical utility of diagnostic tests to identify rhinitis phenotypes and to differentiate between atopy and respiratory allergy in children. 173 children with a clinical suspicion of allergic rhinitis were prospectively evaluated in our pediatric allergist service. The allergological study included clinical history, physical examination, specific IgE (sIgE), skin prick test (SPT), and nasal allergen challenge (NAC). It identified 4 phenotypes: i) allergic rhinitis (AR): positive NAC, SPT and/or sIgE, ii) local allergic rhinitis (LAR): positive NAC and negative SPT and sIgE, iii) dual allergic rhinitis (DAR): positive NAC to perennial & seasonal allergens, SPT and/or sIgE to seasonal and negative to perennial allergens, and iv) non-allergic rhinitis (NAR): negative study. Most of children were girls, with a family history of rhinitis, non-smokers and an urban habit. The mean age of onset of symptoms was 10 (3.982) years. 45,7% had a diagnosis of AR, 24,9% LAR, 11,6% DAR and 17,9% NAR. Atopy was detected by SPT in 57.3%, by sIgE (54.9%), no patient with negative SPT had positive sIgE. However, 36.5% of allergic patients were not correctly classified by these tests being diagnosed by clinical history+NAC. Clinical history and NAC were the most useful diagnostic methods for correctly diagnose respiratory allergy in children. sIgE did not improve the detection of atopy obtained by SPT, and could be avoided as atopy screening-test.

Duration of allergen immunotherapy for inhalant allergy.

We evaluated the time-course of clinical and immunologic changes that occur during and after cessation of sublingual and subcutaneous allergen immunotherapy for inhalant allergies. Increases in production of inhibitory cytokines, such as IL-10 and allergen-specific IgE and IgG4 antibodies are induced within weeks of starting immunotherapy for both seasonal and perennial allergens. In general, 2-4 months' immunotherapy is needed for onset of efficacy whereas maximal clinical effect is achieved within 1-2 years of treatment. Therefore, assuming optimal patient selection, good compliance and at least moderate allergen exposure, if immunotherapy is ineffective at 2 years, it is reasonable to discontinue the treatment. For long-term clinical efficacy, at least 3 years of either subcutaneous or sublingual immunotherapy is required and this results in clinical and immunologic tolerance -- persistence of clinical benefits and suppression of type 2 immunity for years after discontinuation of treatment. Both sublingual and subcutaneous immunotherapy are effective and well tolerated for respiratory allergy. Clinical and immunological changes occur at early stages of treatment. Long-term evaluations support recommendations in international guidelines that both routes of administration should be continued for a minimum of 3 years to achieve disease modification and long-term tolerance.

Determination and analysis of allergen specific IgE in 1 028 children with allergic dermatosis

Objective To observe the differences in specific IgE of allergic diseases. Methods The allergens in 1 028 patients (including 606 cases of eczema/specific dermatitis, 319 Cases of urticaria, 103 cases of papular urticaria and prurigo) were detected by German Allergy Screen Immune mark method. Results There were statistically significant differences (P 3-year-old group was dust mite (10.77%), cockroach (3.52%), Penicillium notatum/Piptocephalis/ aspergillus fumigatus/aspergillus niger/Alternaria (21.32%), Short ragweed/artemisia/Humulus scandens/quinoa (14.73%). The positive rate of specific IgE against house dust in the third quarter was the highest (17.78%) and the difference was statistically significant (χ2=14.443, P=0.002). Among the statistically significant difference in the positive rate of specific IgE between eczema/atopic dermatitis in different age groups (χ2=10.204, P=0.006), the positive rate in the group of 1 to 3 years was the highest. Conclusions Different diseases, ages, and seasonal specific allergens are different, individualized treatment can be carried out according to disease types, ages and seasons. Key words: Anaphylaxis; Allergens; Immunoglobulin E; Child

Early life environmental exposure in relation to new onset and remission of allergic diseases in school children: Polish Mother and Child Cohort Study.

Background: This study was based on data from the Polish Mother and Child Cohort Study. Objective: The aim was to study associations between home environment factors and allergic diseases at 1 year of life and new onset and remission of children's allergy diagnosis at ages 7-9 years. Methods: Children's health status was assessed at ∼12 months of age and then at ages between 7-9 years by using a questionnaire administered to the mothers. Children were assessed by pediatrician/allergists. The patients, who were 7-9 years old, underwent skin-prick tests. Exposure to tobacco smoke was evaluated with a questionnaire addressed to parents and/or caregivers and cotinine measurements were taken of mother's saliva during pregnancy and in children's urine at ages 7-9 years. Incidence and remission were calculated by comparing symptoms in the first year of life with symptoms at 7-9 years. We studied the associations among demographic data, home environment, and new onset and remission of food allergy, atopic dermatitis, and asthma and allergic rhinitis in logistic regression analysis. All associations were adjusted for independent risk factors of dependent variables. Results: Data from 211 participants were included in the analysis. During the first year of life, food allergy was the most common symptom (39%), followed by atopic dermatitis (35%) and asthma (12%). When comparing diagnoses at ages 7-9 years with the first year of life, food allergy had decreased by as much as 18.6%, atopic dermatitis decreased by as much as 23.8%, and asthma decreased by as much as 8%, whereas asthma and allergic rhinitis had increased from 6% to 14.8%. More frequent house cleaning negatively correlated with the new onset of atopic dermatitis and of asthma and allergic rhinitis. Hypersensitivity to seasonal allergens and mites and to any other allergen positively correlated with new onset of food allergy, atopic dermatitis, and asthma and allergic rhinitis. Parental atopy positively correlated with the new onset of asthma and negatively correlated with asthma remission. Conclusion: Analysis of our findings indicated that new onset and/or remission of allergic diseases was linked with hypersensitivity to house-dust mites in children who were polysensitized and with parental atopy. In addition, children who had food allergy, allergic rhinitis, or atopic dermatitis at the age of 1 year had more of a chance developing other atopic disease (except asthma) at ages 7-9 years and less of a chance of having a remission of the disease.

Number of seasonal exposures to Japanese cedar pollen increases the risk of sensitization: Observational study in Korean adults

Sensitization to seasonal allergens usually requires repeated exposure to them. However, research on the extent of exposure that increases the risk of sensitization to specific allergens is lacking. Therefore, we investigated the levels of exposure to Japanese cedar pollen that increased the risk of sensitization to it. A cross-sectional study was conducted with 857 college students living in Jeju, South Korea, as it is the only province in Korea where Japanese cedar pollen levels are high. Questionnaires about demographic characteristics were distributed and skin prick tests for allergic sensitization were performed. Sensitization rates of groups divided by residence period were 3.8% (less than 1 year), 1.8% (1–2 years), 8.5% (2–3 years), 10.3% (3–4 years), 14.8% (4–10 years), and 19.1% (over 10 years). Residence period was an influencing factor of sensitization rate to Japanese cedar pollen, and the cut-off value of the residence period that increased the risk of sensitization to Japanese cedar pollen was found to be 25 months. Repeated exposure to seasonal allergens was related to an increased sensitization rate in young adults. Our results suggested that exposure to Japanese cedar pollen for over two seasons could increase the risk in Korean adults.

Is atopy a risk indicator of chronic obstructive pulmonary disease in dairy farmers?

Allergic mechanisms related to environmental and occupational exposure have been suggested to contribute to the development of chronic obstructive pulmonary disease (COPD).ObjectivesTo investigate the relationships between atopy markers, persistent airflow limitation (PAL) and occupational exposure in dairy farmers.MethodsClinical and biological (total IgE and 21 allergen specific IgE) markers of atopy were assessed in 101 dairy farmers with PAL (DF-PAL), 85 non-farmers with PAL (NF-PAL) (both groups were prospectively included from a screening program performed between 2011 and 2015), and matched controls, i.e. 98 farmers without PAL (DF-controls) and 89 non-farming subjects without PAL (NF-controls). Occupational exposure in farmers was estimated using a validated questionnaire.ResultsPrevalence of allergy history was significantly higher in DF-PAL and in NF-PAL than in controls. Polysensitization, and sensitization to seasonal and food allergens were more frequent in DF-PAL than in DF-controls, respectively: 13.8% vs 1% (adjusted odds ratio (aOR): 17.5 (2.2–134), 11.9% vs 3.1% (aOR: 4.4 (1.2–7.2) and 16.8% vs 4.1% (aOR: 5.2 (1.7–7.2)). The prevalence of atopy markers was similar between NF-PAL patients and NF-controls.ConclusionsPAL in farmers is associated with a high rate of markers of atopy, supporting atopy as a risk indicator.Clinical trial registered with ClinicalTrials.gov (NCT02540408).

Health effects of diesel engine exhaust emissions exposure (DEEE) can mimic allergic asthma and rhinitis

BackgroundPatients presenting to Accident and Emergency (A&E) facilities with dyspnoea, coughing, wheezing and nasal blockage are presumed to have allergic asthma and/or rhinitis. Occupational asthma (OA), which has similar symptoms is rarely considered. Triggers of OA include exposure to diesel engine exhaust emissions exposure (DEEEE) that are carcinogenic. We report the case of a patient who presented to an A&E facility with asthma-like symptoms, was treated for allergic asthma. Frequent exacerbations were experienced. Upon investigations it was shown that were symptoms triggered by DEEE exposure.Case presentationA 36-year-old female bank employee was referred for the evaluation of suspected asthma. She reported a 3-month history of symptoms suggestive of asthma and rhinitis, for which she had previously required A&E treatment. There was no history of atopy. The symptoms only occurred at work or after work. Their onset had coincided with changing offices to one located proximal to a diesel-powered electricity generator. A diagnosis of asthma had been made at the A&E facility and the appropriately used inhaled fluticasone and salbutamol provided limited relief. Skin prick testing was weakly positive for seasonal pollen and house dust mite allergens. Allergen specific IgE tests for 16 regionally relevant aeroallergens were negative. Tests to exclude connective tissue diseases were positive for the anti-Ro-52/TRIM-21 autoantibody. Baseline spirometry values were markedly reduced and bronchodilator administration showed limited reversibility, FEV1 (+ 8%), PEF (+ 5%). Following a 10-day discontinuation of work exposure, the symptoms abated and FEV1 and PEF increased by 10–14% from baseline. The recent onset of asthma, in a non-atopic adult, with workday related symptoms and improvement upon discontinuation of exposure were attributed to passive occupational exposure to DEEE. The diesel generator was relocated, a short course of inhaled fluticasone and oral prednisolone was prescribed and symptoms resolved. This is the first report of the health effects of DEEE mimicking asthma and rhinitis in Zimbabwe.ConclusionsAtypical presentations of adult onset asthma in the absence of a history of either atopy or allergen specific IgE antibody sensitization should trigger in-depth evaluation of occupational exposure in all cases including office workers. Serial monitoring of lung function values should be used for diagnostic and monitoring of the patients.