not-yet-known not-yet-known not-yet-known unknown Regional Patterns of Molecular Sensitization to House Dust Mites and Pollens in Portuguese Children: multicentric study

not-yet-known not-yet-known not-yet-known unknown Identifying molecular sensitization profiles in different regions is key to improve allergy diagnosis and treatment. This multicentric retrospective study analysed the results of 1010 ImmunoCAP ISAC® test performed in pediatric patients from 14 Portuguese hospitals. Sensitization to house dust mite (HDM) molecular allergens was found in 63.9% of patients, mainly to Der p 1, Der p 2, and Der p 23. Among monosensitized individuals Der p 23 stood out, underscoring its clinical significance for allergen-specific immunotherapy (AIT). Urbanization and coastal residence were associated with a higher risk of HDM sensitization, particularly to Dermatophagoides species. In contrast, no regional differences were observed for Lepidoglyphus destructor and Blomia tropicalis, potentially due to climate change and migratory flows, which may be altering traditional allergen distributions. Pollen sensitization affected 56.9% of patients, with grass pollens—mainly Phl p 1 and Cyn d 1—being the most prevalent. Sensitization increased with age, with Phl p 1 emerging as the dominant allergen after early childhood. Interior regions, characterized by greater vegetation, showed a significantly higher prevalence of pollen sensitization. Particular regional trends that reflected the native flora were noted, such as elevated sensitivity to Ole e 1 in Trás-os-Montes and Cup a 1 in Coimbra. Sensitization to Bet v 1 and related PR-10 proteins was associated with food allergy, though inland patients showed a higher rate of primary Bet v 1 sensitization without increased food allergy risk. These results highlight the importance of integrating regional allergen profiles into clinical practice to enhance diagnostic accuracy and guide tailored interventions. Regional Patterns of Molecular Sensitization to House Dust Mites and Pollens in Portuguese Children: multicentric study not-yet-known not-yet-known not-yet-known unknown Portuguese Pediatric Molecular Sensitization João Nogueira Oliveira1, Mafalda Moreira2, Manuel Lima Ferreira2, Sandra Teixeira2, Marta Santalha3, Teresa São Simão3, Armandina Silva3, Filipa Almeida4, Hernani Brito4 Fernanda Carvalho4, Estefânia Maia5, Carla Chaves Loureiro5, Catarina Leuzinguer5, Sara Machado6, Cláudia Pedrosa6, Patricia Silva Veríssimo7, Sofia Guedes7, Carla Rosa7,Georgeta Oliveira8, Ana Paula Aguiar8, Catarina Freitas8, Lara Torres9, Maria Alexandra Rodrigues9, Pedro Guerra9, Helena Ramalho10, Beatriz Sousa10, Mariana Branco10, Ana Sofia Nunes11, Mariana Oliveira Pereira11, Margarida Reis Morais11, José Fraga12,Inês Falcão13, Maria José Dinis13, Conceição Silva13, Raquel Santos14, Rita Silva Pereira14, Márcia Quaresma14, Diana Pinto1, Ana Rita Araújo1 Pediatric department, Unidade Local de Saúde do Santo António Pediatric department, Unidade Local de Saúde do Tâmega e Sousa Pediatric department, Unidade Local de Saúde do Alto Ave Pediatric department, Unidade Local de Saúde do Médio Ave Pediatric department, Unidade Local de Saúde de Coimbra Pediatric department, Unidade Local de Saúde de Gaia e Espinho Pediatric department, Unidade Local de Saúde da Lezíria Pediatric department, Unidade Local de Saúde de Matosinhos Pediatric department, Unidade Local de Saúde da Guarda Pediatric department, Unidade Local de Saúde do Alto Minho Pediatric department, Unidade Local de Saúde de Braga Pediatric department, Unidade Local de Saúde do Nordeste Pediatric department, Unidade Local de Saúde da Povoa de Varzim e Vila do Conde Pediatric department, Unidade Local de Saúde do Trás-Os-Montes E Alto Douro not-yet-known not-yet-known not-yet-known unknown Corresponding author: João Nogueira Oliveira, Pediatric department, Unidade Local de Saúde do Santo António. Contact information: +351919287256, [email protected] Identifying molecular sensitization profiles in different regions is key to improve allergy diagnosis and treatment. This multicentric retrospective study analysed the results of 1010 ImmunoCAP ISAC® test performed in pediatric patients from 14 Portuguese hospitals. not-yet-known not-yet-known not-yet-known unknown Sensitization to house dust mite (HDM) molecular allergens was found in 63.9% of patients, mainly to Der p 1, Der p 2, and Der p 23. Among monosensitized individuals Der p 23 stood out, underscoring its clinical significance for allergen-specific immunotherapy (AIT). Urbanization and coastal residence were associated with a higher risk of HDM sensitization, particularly to Dermatophagoides species. In contrast, no regional differences were observed for Lepidoglyphus destructor and Blomia tropicalis, potentially due to climate change and migratory flows, which may be altering traditional allergen distributions. Pollen sensitization affected 56.9% of patients, with grass pollens—mainly Phl p 1 and Cyn d 1—being the most prevalent. Sensitization increased with age, with Phl p 1 emerging as the dominant allergen after early childhood. Interior regions, characterized by greater vegetation, showed a significantly higher prevalence of pollen sensitization. Particular regional trends that reflected the native flora were noted, such as elevated sensitivity to Ole e 1 in Trás-os-Montes and Cup a 1 in Coimbra. Sensitization to Bet v 1 and related PR-10 proteins was associated with food allergy, though inland patients showed a higher rate of primary Bet v 1 sensitization without increased food allergy risk. These results highlight the importance of integrating regional allergen profiles into clinical practice to enhance diagnostic accuracy and guide tailored interventions.

Molecular allergology, Pediatric allergy,House dust mite sensitization, Pollen allergy,Regional allergy patterns, Precision medicine

Understanding which allergens are most common in a specific geographic location is critical for accurate diagnosis, treatment, and prevention of allergic disorders. Local environmental factors such as plant species, urbanization level, and climate influence the kind and intensity of allergen exposure, resulting in regional variance in allergic responses. The development of precision medicine and the ability to detect allergen molecular components resulted in a paradigm shift in the treatment of these diseases. ImmunoCAP ISAC (Immuno Solid-phase Allergen Chip) is an advanced in vitro diagnostic tool that enables comprehensive profiling of allergen-specific IgE responses using microarray technology. Unlike traditional methods that test for whole allergen extracts, ImmunoCAP ISAC employs purified, recombinant, and native allergen molecules, allowing for a more detailed analysis of IgE sensitization patterns at the molecular level. This approach enhances the ability to differentiate between primary sensitization and cross-reactivity, aiding in more precise allergy risk assessment and tailored patient management. In Portugal there is a lack of understanding about each molecular allergen’s epidemiology, distribution, and clinical importance in children. The goal of this study is to identify the prevalence of each molecular allergen in the Portuguese paediatric population and evaluate its association with geographic location, thereby offering a comprehensive picture of our country’s allergy map.

Retrospective study performed in 14 hospitals from Portugal. We included all paediatric patients (n=1010) that had performed ImmunoCAP® ISAC 112 between January 2020 and January 2025. The collected variables included coexisting allergic diseases (asthma, allergic rhinoconjunctivitis, atopic dermatitis and food allergies) and their residency (defined by their reference hospital centre). The hospitals were then grouped according to the Portuguese NUTS III divisions (Nomenclature of Territorial Units for Statistics). All NUTS were classified as being either coastal or interior and as having either high urban density or low urban density according to their demographic characteristics. Pollinic maps were used to compare the results with the natural distribution of the allergens in each region. A descriptive analysis was performed, and Statistical analysis was performed using SPSS version [25.0] (IBM Corp., Armonk, NY, USA) to estimate associations between molecular allergens and specific regions of Portugal as well as the risk of coexisting diseases.

A total of 1010 patients were enrolled, with slightly male preponderance (63.0%) and a median age of 9 years old (IQR 5–13). Most of the patients came from high-density regions (n=665; 65.0%) and coastal locations (n=609; 60.0%).The included NUTS III were: Porto Metropolitan Area (n=401; coastal and high urban density), Trás-os-Montes e Alto Douro (n=161; Interior and low urban density), Minho e Alto Minho (n=126; Coastal and high urban density), Guarda (n=102; interior and low urban density), Santarém (n=82; Coastal and low urban density), Coimbra (n=80; interior and high urban density) and Tâmega e Sousa (n=58; interior and high urban density). The groups examined in this study exhibit similar demographic characteristics, including gender distribution, age range, and other relevant factors (coexisting allergic diseases). The exam was primarily conducted as an adjunct to immunotherapy selection in patients with multiple sensitizations (53.5%), followed by those with multiple food allergies (34.9%). The most common disease was allergic rhinoconjunctivitis, present in 62,0% of the patients followed by food allergy and asthma (50.5% and 45.3% respectively) and lastly atopic dermatitis present in 31.5% of the patients. House dust mite (HDM) allergens - Results Sensitization to at least one HDM molecular allergen was identified in 63.9% (n=645) of the patients. Among these patients, sensitization to Dermatophagoides pteronyssinus was the most prevalent with Der p 1 being the most common molecular allergen (74.4%) followed by Der p 2 and Der p 23 (72.7% and 72.1% respectively). Dermatophagoides farinae molecular allergens, Der f 1 and Der f 2, were present in 66.9% and 71.0% respectively. Sensitization to both Lepidoglyphus destructor and Blomia tropicalis was lower, being present in 36.4% and 15.0% of the population each. Der p 10 sensitization, a minor allergen of HDM but responsible for cross reactivity with shrimps and other crustaceans, was found in 9.4% of the patients. Of these patients 93.6% were also sensitized to Pen m 1, a tropomyosin responsible for the cross reactivity between HDM and shrimp. There were 96 patients (9.5%) monosensitized to only one HDM molecular allergen with almost half of them being sensitized to Der p 23 (47.9%), followed by Der p 1 (26.4%). Sensitization to at least one HDM molecular allergen was associated with an increased risk of presenting allergic diseases, with patients having 2.8 (CI 95% [2.2; 3.7]) and 2.4 (CI 95% [1.8; 3.0]) times the risk of having asthma or rhinoconjunctivitis respectively. Patients sensitized to Der p 10 had 2.7 (CI 95% [1.9; 3.9]) times the risk of having food allergies. There were significant differences in the sensitization patterns between regions as demonstrated in figure 1. The degree of urbanization was associated with an increased risk of sensitization to all HDM molecular allergens as shown in figure 2 with patients from these areas having 4.3 (CI 95% [3.3; 5.7] times the risk of being sensitized to at least one HDM molecular allergen. There was also an increased risk of sensitization to HDM in patients living in coastal areas, but this increase was only significant to Dermatophagoides pteronyssinus and Dermatophagoides farinae as shown in table 1. Pollens molecular allergens – Results We found sensitization to at least one pollen molecular allergen in 56.9% of our patients. Grass pollens were the most prevalent group, especially Phl p 1 and Cyn d 1, that were positive in 47.2% and 35.8% respectively. As represented in figure 3 we demonstrated sensitization to grass pollens increases with age across the population. Phl p 1 becomes the major allergen in patient older than 3, but in younger patients Cyn d 1 and Phl p 2 were the first allergens to appear, in 5.0% and 4.0% respectively. The interior of the country was associated with a significantly increased risk of sensitization to pollens as demonstrated in table 2. Most of the allergens were associated with an increased risk of allergic rhinoconjunctivitis, especially grass pollens which increased the risk by at least 4 times (CI 95% [3.0; 5.7]). Ole e 1 was associated with asthma increasing its risk by 1.8 (CI 95% [1.2; 2.7]). There was significant variation of the sensitization patterns to tree pollens among the regions as demonstrated in figure 5. Ole e 1 was significantly more prevalent in the region of Trás-os-Montes e Alto Douro with patients from this region having 6.9 (CI 95% [4.5; 10.5]) times the risk of being sensitized. Patients from Coimbra also had 3.2 (CI 95% [1.9; 5.6]) times the risk of being sensitized to Cup a 1. There were 61 patients (6.1%) sensitized to Bet v 1, which is a protein of the pathogenesis‐related class 10 (PR‐10) family that is sometimes associated with cross reactivity with Bet v 1-related food proteins. In these patients, sensitization to Aln g 1 and Cor a 1.0101 was found in 67.2% and 59.3% respectively. When analysing the sensitization values to evaluate possible primary sensitization, we identified that patients living in the interior regions had 4.1 (CI 95% [1.4; 12.1]) the risk of being primarily sensitized to Bet v 1. Sensitization to Bet v 1 also increased the risk of developing food allergy (OR 2.1; CI 95% [1.2; 3.6]). House Dust mite (HDM) allergens - Discussion As described in the literature, our results demonstrate that HDM allergens are extremely prevalent being present in more than half of our patients 1 . Persistent inflammation brought on by prolonged exposure to HDM allergens increases the risk of developing respiratory diseases 1 as demonstrated in our population with patients sensitized to HDM allergens having an increased risk of developing asthma, allergic rhinitis and atopic dermatitis. Molecular allergology has shown to be fundamental to choose the most adequate allergen-specific immunotherapy (AIT). Der p 23 is one of the HDM allergens that has been proven to be clinically significant 2 . In our study, Der p 23 was the third most frequently found HDM molecular allergen, and it was the most frequently found in our monosensitized patients, making the inclusion of Der p 23 in immunotherapy essential. The presence of cross-reactive allergens, especially Der p 10, is another important factor in HDM allergen sensitivity 2 . Because of its structural similarity to tropomyosin from other invertebrates, such as shrimp, Der p 10 is known to exhibit cross-reactivity that is clinically significant. Nearly 10% of our patients had sensitization to Der p 10, and almost all of them had cross-reactivity with Pen m 2, highlighting the importance of studying these molecular allergens, as identifying Der p 10 sensitization allows for better risk assessment, dietary recommendations and potential avoidance strategies in affected individuals. HDM sensitization patterns have been linked to environmental conditions, such as the level of urbanization and the distance from sea level 3 . Furthermore, HDM proliferation and allergen load are influenced by temperature and humidity fluctuations 3 . HDM populations are typically higher in coastal places with higher humidity levels, while concentrations of these allergens may be lower in drier inland areas. Understanding these geographical influences on HDM exposure can help tailor preventive measures and guide public health strategies aimed at reducing allergic disease prevalence. With this work we contributed to a better understanding of the distribution of sensitization to HDM in our country as well as the influence of both urbanization level and distance to seashore. As described in the literature we found a significant increase in the sensitization to HDM allergens in the patients that live in more urban regions 4 . In our study this translated an increased risk of sensitization that ranged 2.7 to 7 times the risk. Interestingly, when comparing patients living in the coastal areas to patients located more inland, the increased risk of sensitization was limited to both Dermatophagoides farinae and Dermatophagoides pteronyssinus. Lepidoglyphus destructor and Blomia tropicalis did not show a statistically significant difference. The absence of difference between inland and coastal areas to Lepidoglyphus destructor might be justified by the characteristics of each mite. Lepidoglyphus destructor was initially associated with occupational disease in workers of food storage in farms and agricultural lands, therefore the classification as storage dust mite, but since then has been demonstrated to be an important allergen in people living in both urban and rural areas 5 . The inland of Portugal is usually more rural and associated with older structures which create a perfect environment for the growth of storage dust mites. These findings highlight the importance of considering these allergens when approaching patients sensitized to dust mites who live in these regions. The sensitization pattern to Blomia tropicalis found in our population is also interesting. In tropical and subtropical areas, Blomia tropicalis is a common house dust mite that is known to be a major cause of indoor allergies 6 . This mite grows best in warm, humid conditions with a relative humidity of 70% and temperatures between 25°C and 30°C. The possible effects of global warming on Blomia distribution have been investigated in recent research 3,6 . Rising global temperatures and changed patterns of humidity brought about by climate change may expand the habitats suitable for this mite species. In our patients, unlike what was expected, there was no significant difference between the coastal areas (which would typically be considered a suitable environment) and the more inland regions. This might be explained by the climate changes that have been observed worldwide. Our country has seen significant changes in the climate with the inland areas suffering from higher temperatures, increased heat wave frequency, and altered precipitation patterns 7 . Another possible explanation is the increased migratory flow of patients from areas where Blomia is common like South America 8,9 . These changes might justify the higher-than-expected sensitization to Blomia in our inland population and demonstrate the importance to further study the impact of climate change and migratory flows in our clinical practice. Pollens molecular allergens - Discussion In our study sensitization to pollens was significant with more than half the population being sensitized to at least one allergen. Grass pollens in specific were associated with a significant risk of developing rhinoconjunctivitis, reinforcing the role that these allergens have in the inflammation of the nasal mucosa. As described in the literature our population demonstrated a gradual increase to the number of allergens sensitized as they grow older 10 . This demonstrates that while in early childhood we might find patients monosensitized to Phl p 1 most patients will be sensitized to all grass molecular allergens by the age of 18. As expected, there were significant differences between the different regions of our country regarding the sensitizations. Firstly, when comparing the interior with the coastal areas we see that there is a significant increase in the sensitization to pollens in the interior, which is expected given the increase in vegetation in these areas 11 . Interestingly we found a direct correlation between the number of green spaces and the degree of sensitization, with Santarém being the region with the least amount. When looking at specific regions we found patterns that are direct translation of the pollinic maps of our country 12 . The patients from Trás os Montes e Alto Douro (corresponding to the Douro region) had a significantly increased sensitization to Ole e 1 compared to the other regions. This can be explained when we look at the distribution of olive trees in our country, which are predominantly found in Alentejo and Douro Region. Similarly, there was a significant sensitization to Cup a 1 in Coimbra which also corresponds to the region of distribution of Cypress trees. These differences in the sensitization pattern are important as they allow clinicians of each region to better understand what the most important allergens in their area are. Sensitization to Bet v 1, often related with cross reactivity, was associated with an increased risk of food allergy in our population. Interestingly, when evaluating the primary sensitizer, we found that patients from the interior region had a significantly higher chance of being primarily sensitized by Bet v 1 and, unlike the remaining patients, shown no increased risk of food allergy. This aligns with the distribution of Betula in our country which is predominantly found in the interior regions 12 . These results are important as different sensitization pathways can translate distinct clinical behaviours as postulated in some studies 13 .

The findings of this research emphasize the need of incorporating these regional variations into clinical practice and draw attention to the notable regional variations in allergy sensitivity patterns among Portuguese children. The need for a more individualized approach to the diagnosis and treatment of allergy illnesses is highlighted by the difference in sensitization profiles that are impacted by climatic, urbanization, and geographic factors. The sensitization pattern to Blomia tropicalis, presents a compelling case for considering the impacts of climate change and migratory flows in clinical practice. Despite expectations of higher prevalence in coastal regions due to warmer and more humid conditions, our findings revealed no significant difference between coastal and inland areas. This unexpected pattern may be explained by rising global temperatures, altered precipitation patterns, and increased migratory flows from regions with a higher prevalence of Blomia tropicalis. These factors highlight the importance of ongoing surveillance and adaptability in clinical guidelines to address the evolving landscape of allergen exposure. Additionally, the high prevalence of sensitization to Der p 23 among patients, particularly those who are monosensitized, underscores its clinical significance and the need for its inclusion in allergen-specific immunotherapy (AIT) formulations. The underrepresentation of Der p 23 from AIT could result in suboptimal treatment outcomes for a significant subset of patients, emphasizing the importance of incorporating region-specific allergen profiles into treatment protocols to enhance efficacy and achieve better clinical management of allergic diseases. Another notable result is the sensitization to Bet v 1, primarily associated with birch pollen, which exhibited distinct patterns between coastal and interior regions. The higher prevalence of primary sensitization to Bet v 1 in the interior regions aligns with the high distribution of Betula in this region and suggests that sensitization pathways differ significantly based on local vegetation. This differentiation is clinically significant, as patients from the interior showed no increased risk of food allergies compared to those in birch-free areas, indicating the necessity for region-specific diagnostic and management strategies. In summary, incorporating regional allergen profiles into clinical guidelines could lead to more effective prevention strategies and personalized treatment plans, ultimately reducing the burden of allergic diseases. Future research should continue to explore the impact of environmental changes, migratory patterns, and regional allergen extending the study to the remaining country. Conflicts of interest: The authors declare no conflict of interest. not-yet-known not-yet-known not-yet-known unknown References: Miller, Jeffrey D. ”The role of dust mites in allergy.” Clinical reviews in allergy & immunology 57.3 (2019): 312-329. Dramburg, Stephanie, et al. ”EAACI molecular allergology user’s guide 2.0.” Pediatric Allergy and Immunology 34 (2023): e13854. Acevedo, Nathalie, Josefina Zakzuk, and Luis Caraballo. ”House dust mite allergy under changing environments.” Allergy, asthma & immunology research 11.4 (2019): 450-469. Adgate, John L., et al. ”Allergen levels in inner city homes: baseline concentrations and evaluation of intervention effectiveness.” Journal of exposure science & environmental epidemiology 18.4 (2008): 430-440. Kaya, Mehmet Akif, et al. ”The Role of Climate and Residency in Storage Mite Sensitivity Among Children with Allergic Diseases in The Mediterranean Region.” International Archives of Allergy and Immunology (2025): 1-16. Caraballo, Luis, et al. ”Blomia tropicalis: A 50-Year History.” The Journal of Allergy and Clinical Immunology: In Practice (2024). Lima, Daniela CA, et al. ”A multi-variable constrained ensemble of regional climate projections under multi-scenarios for Portugal–part II: sectoral climate indices.” Climate Services 30 (2023): 100377. Peixoto, Joao. ”Back to the south: Social and political aspects of Latin American migration to Southern Europe.” International Migration 50.6 (2012): 58-82. Daschner, Álvaro, et al. ”Imported subclinical house dust mite sensitisation in migrants from geohelminth-endemic developing countries.” Allergologia et immunopathologia 37.3 (2009): 165-167. Lindqvist, Magnus, et al. ”Natural course of pollen‐induced allergic rhinitis from childhood to adulthood: A 20‐year follow up.” Allergy 79.4 (2024): 884-893. Gouveia, Célia, and Carlos C. DaCamarab. ”Land Cover Map for Portugal using VEGETATION data.” Camacho, Irene, et al. ”Airborne pollen calendar of Portugal: a 15-year survey (2002–2017).” Allergologia et immunopathologia 48.2 (2020): 194-201. Elisyutina, Olga, et al. ”Bet v 1-specific IgE levels and PR-10 reactivity discriminate silent sensitization from phenotypes of birch allergy.” Allergy 74.12 (2019): 2525. Tables: Table 1.: Odds ratio of sensitization to house dust mites in relationship with geographic location: | OR of sensitization to house dust mites [CI 95%] | ||||||| | Der f 1 | Der f 2 | Der p 1 | Der p 2 | Der p 23 | Blo t 5 | Lep d 2 | | | High urbanization | 3.4 [2.6 . 4.6] | 3.8 [2.8 . 5.0] | 2.7 [2.1 . 3.6] | 5.0 [3.8 . 6.7] | 4.3 [3.2 . 5.7] | 4.9 [3.2 . 8.1] | 2.5 [1.8 . 3.4] | | Coastal areas | 2.1 [1.6 . 2.8] | 2.6 [1.9 . 3.3] | 2.2 [1.7 . 2.9] | 2.7 [2.1 . 3.5] | 2.5 [1.9 . 3.3] | X | X | Table 1: Odds ratio of being sensitized to each molecular allergen in children living in high urbanization areas and in coastal areas. High urbanization is associated with an increased risk of sensitization to all allergens while coastal areas are associated with an increased risk to all but Blo t 5 and Lep d 2. Table 2.: Odds ratio of sensitization to pollens in the interior of the country versus the coastal areas: | OR of sensitization to pollens in the interior versus coastal areas [CI 95%] | |||| | Cyn d 1 | 1.7 (1.3-2.3) | Cup a 1 | 2.3 (1.6-3.5) | No statistically significant difference for Phl p 1, Ole e 9, Par j 2 and Pla l 1 | | Phl p 2 | 1.7 (1.3-2.3) | Ole e 1 | 4.7 (3.1-7.3) | | | Phl p 4 | 2.1 (1.6-2.9) | Cry j 1 | 2.2 (1.4-3.6) | | | Phl p 5 | 2.6 (1.9-3.5) | Bet v 1 | 1.9 (1.1-3.1) | | | Phl p 6 | 2.6 (1.9-3.8) | Art v 1 | 4.7 (1.7-13.1) | | | Phl p 11 | 2.3 (1.5-3.5) | Che a 1 | 1.9 (1.1-3.8) | Table 2: Odds ratio of being sensitized to each pollen molecular allergen in children living in the interior regions versus coastal areas. There is an increased risk of sensitization to most of them in children living in the interior of the country where these pollens are more present. Figure legends: Figure 1.: Sensitization patterns to house dust mite by NUTS III regions Figure 2.: Relationship between HDM sensitization and geographic location Figure 3.: Evolution of the sensitization to grass pollens according to age Figure 4.: Difference in the sensitization to pollens between the interior and the coastal areas. Figure 5.: Tree pollen distribution by NUTS III Region Information & Authors Information Version history Copyright This work is licensed under a Non Exclusive No Reuse License.

Authors Metrics & Citations Metrics Article Usage 269views 161downloads Citations Download citation João Nogueira Oliveira, Mafalda Moreira, Manuel Lima Ferreira, et al. not-yet-known not-yet-known not-yet-known unknown Regional Patterns of Molecular Sensitization to House Dust Mites and Pollens in Portuguese Children: multicentric study. Authorea. 18 June 2025. DOI: https://doi.org/10.22541/au.175024294.40174779/v1 DOI: https://doi.org/10.22541/au.175024294.40174779/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu.