Allergen Sensitization in Atopic Dermatitis: Distinction from Controls and Prediction of Respiratory Allergies

Abstract

Introduction

Atopic dermatitis (AD) is a common inflammatory skin condition characterized by epidermal barrier dysfunction and immune dysregulation, affecting both children and adults. This study aimed to determine the prevalence of common allergen sensitizations in patients with AD, compared with controls without allergic diseases, and to identify those associated with an increased risk of asthma or allergic rhinitis.

Methods

We conducted a cross-sectional study including patients with AD and age- and sex-matched controls selected by propensity score matching from the Center of Allergy and Clinical Immunology, Vinmec Times City Hospital. Total IgE levels and specific IgE sensitization to common allergens were documented using an extract-based multiplex assay.

Results

Both the AD and control groups each comprised 452 patients and were comparable in age, median (IQR, range): 7 (1–29, 0–84), and sex distribution (51.11% female). Sensitization to at least one allergen was observed in 59.51% of patients, with a mono-sensitization rate of 11.73% and a poly-sensitization rate of 47.79%. House dust mites had the highest sensitization rates among AD patients in our study, with sensitization rates for Dermatophagoides pteronyssinus, D. farinae, and Blomia tropicalis at 29.65%, 26.99%, and 11.5%, respectively. Eggs and milk were the most common food allergens, with sensitizations rates of 20.58% and 12.61%, respectively. Although sensitization rates were high, the prevalence of true clinical allergy was much lower, underscoring the need for cautious interpretation of test results in conjunction with clinical symptoms. Age-related differences were evident: younger children were more often sensitized to food allergens, older children and adolescents to respiratory allergens, and elderly patients to cockroach, and Candida albicans. Additionally, sensitization to C. albicans, D. pteronyssinus, D. farinae, cat dander, dog dander, rice grain, barley flour, and rye flour was significantly more frequent in patients with AD compared to individuals with no allergic diseases. Such sensitization was also associated with a higher risk of respiratory allergic comorbidities, suggesting the potential role of these allergens as distinctive markers of atopy.

Conclusion

This study highlights the importance of understanding allergen sensitization in patients with AD to optimize management strategies, particularly in Vietnam, where house dust mite sensitization is highly prevalent. Allergen avoidance and allergen-specific immunotherapy could be beneficial as add-on therapies for AD.

Introduction

Atopic dermatitis (AD) is a heterogeneous inflammatory skin disease that affects both children and adults. Its pathophysiology is primarily driven by two intertwined mechanisms: disruption of the epidermal barrier and immune dysregulation [1]. In predisposed and immunologically vulnerable individuals, epidermal barrier dysfunction allows allergens to penetrate the stratum corneum, stimulating Langerhans cells and promoting sensitization to food or airborne allergens. AD is commonly associated with other atopic conditions, such as food allergies, asthma, and allergic rhinitis, which are generally accompanied by elevated serum IgE levels and positive allergen-specific IgE responses [2]. Collectively, these observations suggest a strong pathophysiological link between various atopic diseases and underscore the pivotal role of sensitization and allergic mechanisms in AD. However, the causal relationship between specific allergens – namely, sensitization to food versus aeroallergens – and the severity or exacerbation of AD remains unclear. Most current guidelines recommend allergy testing for patients with moderate-to-severe AD. However, the interpretation of these test results and the subsequent therapeutic decisions – including the implementation of elimination diets and allergen immunotherapy – vary based on local assessments of the benefit-risk ratio, patient preferences, and the financial implications of treatment [3–5].

Recent studies indicate that allergen sensitization profiles vary across countries and regions [6]. Differences in environmental allergen exposure and dietary patterns among different populations may contribute to these geographic variations. For instance, chicken eggs and cow’s milk are the most common food allergens [7–9]. While pollen is the predominant respiratory allergen in European countries, house dust mites are more frequently observed in Asian countries [6]. Additionally, recent studies suggest that allergen sensitization patterns in patients with AD also vary by age and gender [10]. Consequently, a comprehensive understanding of these sensitization characteristics is essential for developing targeted management strategies for allergic diseases within specific national and regional contexts. To date, only a limited number of studies have investigated allergen sensitization profiles in patients – particularly children – with AD in Vietnam [11, 12]. The primary objective of this study was to determine the prevalence of sensitization to common allergens among patients with AD. Secondary objectives included comparing allergen sensitization rates between AD patients and a control group without allergic diseases and identifying specific allergen sensitizations that are most strongly associated with respiratory allergic comorbidities, namely, asthma and allergic rhinitis. By delineating the distinguishing sensitization patterns of AD, highlighting sensitizations that carry the greatest clinical significance for atopy, and providing detailed prevalence data, this work offers valuable evidence to support the selection of diagnostic tests and guide personalized therapeutic strategies.

Methods

Patients and Sample Size Determination

We reviewed data from 452 AD patients examined at the Center of Allergy and Clinical Immunology, Vinmec Times City Hospital, Hanoi, Vietnam, between 2021 and 2023. The diagnosis of AD was made using Hanifin and Rajka’s criteria. Diagnoses of AD and other allergic comorbidities (asthma and allergic rhinitis) were made by staff allergists and clinical immunologists.

The control group was formed from a pool of 817 healthy individuals without allergic diseases (defined as having no diagnosis of AD, asthma, allergic rhinitis, or food allergies, including eosinophilic esophagitis. All individuals underwent a thorough review of their medical records and clinical history by a clinical allergist-immunologist to confirm the absence of any atopic conditions; hereafter referred to as the non-allergic group) and was matched to the case group by age and gender using propensity score matching, resulting in a final sample of 452 individuals.

Sample size was determined to ensure adequate statistical power for estimating the prevalence of common allergen sensitizations and for comparisons between groups. The required sample size was calculated using the formula for estimating a single proportion:

$$n=\frac{Z^2\times p\left(1-p\right)}{d^2}$$

where Z is the standard normal deviate corresponding to the desired confidence level, p is the expected prevalence, and d is the acceptable margin of error.

To obtain the largest and most conservative sample size, we assumed p = 0.5, d = 0.05, and Z = 1.96 (corresponding to a 95% confidence level), which yielded a minimum of 385 participants per group. Allowing for potential missing or incomplete data (10–15%), a slightly larger sample was targeted. Therefore, the available sample of 452 participants per group was considered sufficient to provide reliable estimates of allergen sensitization prevalence and to detect meaningful differences between patients with AD and healthy controls.

Laboratory Measurements

Total immunoglobulin E (IgE) levels were measured using the electrochemiluminescence immunoassays. A commercially available kit (EUROBlotOne; EUROIMMUN Medizinische Labordiagnostika AG, Lübeck, Germany) was used to detect common allergen-specific IgE antibodies in serum through the immunoblot technique, targeting a panel of the most frequently encountered allergens. These included food allergens (egg white, egg yolk, cow’s milk, goat’s milk, beef, pork, chicken, shrimp, codfish, tuna, sardine, wheat flour, rye flour, barley flour, oat flour, rice grain, soybean, corn grain, gluten, peanut, hazelnut, almond, tomato, lemon, orange, strawberry, apple, pineapple); respiratory allergens (Dermatophagoides pterronyssinus, D. farinae, Blomia tropicalis, dog dander, cat dander, American cockroach, chicken feathers, brewer’s yeast, baker’s yeast, Penicillium notatum, Cladosporium herbarum, Aspergillus fumigatuss, Candida albicans, Alternaria alternata, Bermuda grass, dandelion); venom allergens (honey bee, common wasp, fire ant, mosquito); and latex. Sensitization was considered positive if the intensity value was greater than 5 or when the corresponding specific IgE level was ≥0.35 U/mL.

Outcomes and Measures

The primary outcome was the prevalence of sensitization to specific allergens in patients with AD. Secondary outcomes included the number of allergens sensitized per patient, the distribution of sensitizations across subgroups (e.g., by age, sex, or comorbidities), and the association between specific allergen sensitizations and allergic comorbidities such as asthma or allergic rhinitis.

Quantitative measures included the total number of allergens each patient was sensitized to and the frequency and percentage of patients sensitized to each allergen. Qualitative measures included the presence or absence of sensitization to each allergen (yes/no) and subgroup categorization. Analyses included calculating prevalence for each allergen, assessing sensitization burden per patient, comparing frequencies across subgroups (AD vs. no allergic diseases controls), and estimating the probability of sensitization to specific allergens according to disease characteristics or comorbidities.

Based on molecular allergology, IgE sensitization to orange, strawberry, lemon, pineapple, apple, and latex is predominantly related to cross-reactive components such as profilins, polcalcins, and cross-reactive carbohydrate determinants and is generally considered clinically irrelevant [13, 14]; therefore, these allergens were excluded from further analyses. In addition, sensitization to hymenoptera venom allergen sources, including Apis (bee), Vespula (wasp), and Solenopsis (ant), is not recommended for inclusion in allergy screening [15, 16] and was therefore excluded from the main analysis.

Statistical Analysis

Data were entered, cleaned, and processed using Python (version 3.13; Python Software Foundation). Quantitative variables were presented as the mean and standard deviation if normally distributed and as the median if non-normally distributed. Qualitative variables were expressed as counts and percentages. Comparisons between two quantitative variables were performed using the t test for normally distributed data and the Mann-Whitney test for non-normally distributed data. Comparisons between two qualitative variables were analyzed using the chi-square test. A p value of less than 0.05 was considered statistically significant.

Ethical Approval

Ethical approval for this study was obtained from the Human Research Ethics Committee of the Vinmec Healthcare System (Approval No. 81/2023/CN/HĐĐĐ VMEC).

Results

Patient Characteristics

Among the 452 AD patients included in the study, 51.11% were female and 48.89% were male. The median age was 7 years (IQR 1–29; range, 2 months–84 years). The AD group and the non-group were nearly identical in terms of age and gender. The median total serum IgE level in AD patients was 116, with a wide range from 1 to 30,134 IU/L, and there was no statistically significant difference compared to the non-allergic group. The median eosinophil count was 0.3 G/L (range: 0–6.9) with a statistically significant difference compared to the non-allergic group (Table 1).

Table 1.

Baseline characteristics of study participants

Feature	AD (n = 452)	Non-allergic group (n = 452)	p value (test)
Sex, n (%)			1.00 (chi-squared)
Female	231 (51.11)	231 (51.11)
Male	221 (48.89)	221 (48.89)
Age, years			0.99 (Mann-Whitney)
Median (IQR, range)	7 (1–29, 0–84)	7 (1–29, 0–84)
Age-group, n (%)			0.99
0–5 years	210 (46.46)	210 (46.46)	(chi-squared)
6–17 years	97 (21.46)	99 (21.90)	​
18–60 years	130 (28.76)	128 (28.32)	​
>60 years	15 (3.32)	15 (3.32)	​
Total IgE, IU/L			0.09 (Mann-Whitney)
Median [min, max]	116 [1, 30,134]	110 [1, 1,475]
Missing, n	111	173
EO, G/L			<0.00001 (Mann-Whitney)
Median [min, max]	0.3 [0, 6.9]	0.195 [0, 2.6]
Missing, n	113	146

AD, atopic dermatitis; IgE, immunoglobulin E; EO, eosinophils.

A linear correlation was found between age and total serum IgE levels in children with AD (under 18 years old) with a Pearson correlation coefficient (R) of 0.37 (p value <0.001) (Fig. 1a). Higher total IgE concentrations were associated with an increased risk of sensitization to allergens. Our study results in patients with AD demonstrated a linear relationship between total IgE concentration and the number of sensitizing allergens, with a Pearson correlation coefficient (R) of 0.69 (p value <0.001) (Fig. 1b).

Fig. 1.

Correlation between total serum IgE levels and age in children with AD (a) and the number of allergen sensitizations (b). IgE, immunoglobulin E.

Characteristics of Allergen Sensitization in AD Patients

Sensitization to at least one allergen was observed in 59.51% of individuals with AD. Among them, 11.72% were monosensitized, while 47.79% were polysensitized, indicating that the majority of sensitized AD patients reacted to multiple allergens. House dust mites were the allergens with the highest sensitization rates among AD patients in our study, with sensitization rates of 29.65%, 26.99%, and 11.5% for D. pteronyssinus, D. farinae, and B.tropicalis, respectively. Eggs and milk were the most common food allergens, with sensitization rates of 20.58% and 12.61%, respectively (Fig. 2).

Fig. 2.

Percentage of sensitization to common allergens in AD patients. C. herbarum, Cladosporium herbarum; A. fumigatus, Aspergillus fumigatus; P. notatum, Penicillium notatum; A. alternata, Alternaria alternata; C. albicans, Candida albicans; D. pter, Dermatophagoides pteronyssinus; D. farinae, Dermatophagoides farinae; B. tropicalis, Blomia tropicalis.

We divided AD patients into four age-groups: infants and preschool children (under 6 years old), school-age children and adolescents (6–17 years old), adults (18–60 years old), and elderly individuals (61 years and older). Figure 3 shows that the school-age and adolescent group had significantly higher sensitization rates to respiratory allergens – such as house dust mites and animal dander – compared to the other groups. Children exhibited a higher prevalence of sensitization to food allergens, whereas elderly individuals showed greater sensitization to cockroach, mold, and insect venom allergens.

Fig. 3.

Prevalence of allergens sensitization by age-group. Chi-square test: *p < 0.001, ^#p < 0.01, ^$p < 0.05. C. albicans, Candida albicans; B. tropicalis, Blomia tropicalis; D. pter, D. pteronyssinus; D. farinae, Dermatophagoides farinae.

The correlation heatmap revealed distinct co-sensitization patterns among allergens in AD patients (Fig. 4). Strong correlations were observed between allergens sharing similar biological origin, such as cereal grains, tree nuts, and house dust mites. These findings indicate a tendency toward cross-sensitization within specific allergen groups.

Fig. 4.

Rate of co-sensitization in AD patient. C. herbarum, Cladosporium herbarum; A. fumigatus, Aspergillus fumigatus; P. notatum, Penicillium notatum; A. alternata, Alternaria alternata; C. albicans, Candida albicans; D. pter, Dermatophagoides pteronyssinus; D. farina, Dermatophagoides farinae; B. tropicalis, Blomia tropicalis.

Comparison of Sensitization Rates between AD Patients and Non-Allergic Controls

Compared with the non-allergic control group, where 48.45% of individuals were sensitized to at least one allergen (13.94% monosensitized and 34.51% polysensitized), AD patients showed a significantly higher overall sensitization rate (59.51%, 11.72% monosensitized, 47.79% polysensitized; p < 0.001, chi-squared test). Notably, the sensitization rate in the control group was also considerable, suggesting that allergen reactivity is not uncommon even in individuals without allergic diseases. As shown in Figure 5, sensitization rates to egg white, egg yolk, shrimp, wheat flour, rye flour, barley flour, oat flour, rice grain, soybean, corn grain, peanut, D. pteronyssinus, D. farinae, cat dander, dog dander, chicken feathers, C. herbarum, C. albicans, and A. alternata were significantly higher in the AD group compared to the control group (p < 0.05). Meanwhile, sensitization rates to the remaining allergens, including cow’s milk, showed no statistically significant difference between the AD group and the control group (p > 0.05) (online suppl. Table 1; for all online suppl. material, see https://doi.org/10.1159/000551372).

Fig. 5.

Prevalence of sensitization to common allergens in AD patients compared with non-allergic diseases groups. Chi-square test: *p < 0.001, ^#p < 0.01, ^$p < 0.05. AD, atopic dermatitis; C. albicans, Candida albicans; D. farinae, Dermatophagoides farinae; D. pter, Dermatophagoides pteronyssinus; A. alternata, Alternaria alternata.

Allergens Sensitization and Associated Risk of Respiratory Allergic Diseases

Among the 452 AD patients, 90 (19.91%) presented with comorbid respiratory allergic diseases. Asthma was observed in 3.54%, allergic rhinitis in 13.27%, and both conditions in 3.10% of the patients. Respiratory allergic comorbidities were more frequently observed in the 6–60-year age-group, particularly among older children and adolescents with AD (Fig. 6a). There was no statistically significant difference in the prevalence of comorbid asthma and/or allergic rhinitis between females and males (Fig. 6b). Patients with AD comorbid with asthma and/or allergic rhinitis had higher total IgE levels (Fig. 6c) and a greater number of sensitized allergens (Fig. 6d) compared with those with AD alone.

Fig. 6.

Clinical characteristics of the group with AD only compared with the AD group comorbid with asthma and/or allergic rhinitis by age-group (a), sex (b), total IgE (c), and number of sensitized allergens (d). AD, atopic dermatitis; A/AR, asthma and/or allergic rhinitis; IgE, immunoglobulin E.

The AD group with respiratory allergic comorbidities showed a higher overall rate of sensitization to inhalant allergens, particularly house dust mites, cat dander, C. ambican, and dog dander, compared with the AD-only group (Fig. 7a). AD patients sensitized to D. pteronyssinus, D. farinae, B. tropicalis, cat hair, barley flour, C. herbarum, C. albicans, rye flour, and dog dander had a higher risk of concomitant respiratory allergic diseases. Odds ratios for respiratory allergens are shown in Figure 7b, whereas odds ratios for all tested allergens are detailed in online supplementary Table 2.

Fig. 7.

Association of inhalant allergen sensitization with comorbid asthma and/or allergic rhinitis in patients with AD: sensitization rates (a) and ORs (b). Chi-square test: *p < 0.001, ^#p < 0.01, ^$p < 0.05. AD, atopic dermatitis; A/AR, asthma and/or allergic rhinitis; C. herbarum, Cladosporium herbarum; D. pter, Dermatophagoides pteronyssinus; D. farinae, Dermatophagoides farinae; B. tropicalis, Blomia tropicalis; P. notatum, Penicillium notatum; A. alternata, Alternaria alternata; C. albicans, Candida albicans; A. fumigatus, Aspergillus fumigatus.

Discussion

Allergen sensitization patterns vary notably across geographical regions and countries. In Western Europe and the USA, the predominant allergens are house dust mites, cockroaches, and pollen, with high sensitization rates reported [17, 18]. In contrast, Eastern and Northern Europeans primarily see sensitization to pet dander – specifically, dog and cat dander – in addition to pollen [18]. In Asia, house dust mites are the dominant allergens, with sensitization rates reaching as high as 90% among atopic patients, whereas sensitization to pollen and animal dander occurs at substantially lower rates (typically below 10%) [6]. Data from Vietnam similarly indicate that house dust mites are among the allergens with the highest sensitization rates in atopic patients [11, 19]. Nonetheless, data on sensitization rates in patients with AD in Vietnam remain limited. Our findings indicate that house dust mites, egg whites, cow’s milk, and almonds are the most prevalent allergens in AD patients, with sensitization rates exceeding 10%. Recent studies conducted in Egypt, Turkey, and China support these observations, revealing that house dust mites, eggs, and milk are common allergens in AD patients [7, 10, 20–22]. The elevated sensitization to house dust mites observed in atopic patients in Vietnam and other tropical regions probably can be attributed to the warm and humid climate, which creates conditions highly conducive to the proliferation of these mites.

In addition, we assessed sensitization rates across different age-groups. Our analysis revealed that children under the age of 6 exhibited significantly higher sensitization rates to food allergens – including eggs, milk, beef, peanuts, and soybeans – compared to older children and adults. This phenomenon may be attributed to the relative immaturity of their immune and digestive systems, which makes them more susceptible to early sensitization [23]. Egg and milk were among the most common sensitizing allergens and were detected in both children aged ≥6 years and adults. Nevertheless, in the majority of older children and adults, sensitization to egg or milk appeared to be clinically silent, in accordance with the natural history of these food allergies [24, 25]. A similar trend is increasingly observed for other allergens among elderly individuals. Our study showed that although the prevalence of sensitization to beef was high, the majority of these patients also exhibited concomitant sensitization to cow’s milk (Fig. 5). Therefore, this sensitization is more likely attributable to bovine serum albumin rather than representing a true clinical beef allergy, with no associated clinical symptoms following beef consumption. Epidemiological evidence further indicates that both allergen sensitization and food allergies are more prevalent in the pediatric population than in adults. Despite the elevated sensitization rates to food allergens observed in children with AD, the prevalence of clinically confirmed food allergies remains comparatively low. Consequently, it is essential to interpret allergy test results within the context of a comprehensive medical history to avoid unwarranted dietary restrictions. Overly restrictive diets could complicate meal planning and potentially have adverse effects on the nutritional development of affected children [3, 26]. Moreover, our study found that children aged 6–17 exhibited significantly higher sensitization rates to respiratory allergens – particularly house dust mites and animal dander – comparative to both younger children and adults. These findings suggest that pediatric patients with AD in this age-group are more likely to present with a genuine atopic profile, which is frequently associated with an increased prevalence of comorbidities such as asthma and allergic rhinitis.

The correlation heatmap reveals distinct patterns of co-sensitization among allergens in AD patients. Several allergen pairs or groups demonstrated moderate to strong correlations, particularly those that are taxonomically related or share similar biological sources. For example, strong co-sensitization was observed among cereal grains (e.g., wheat, rye, barley, and oat), tree nuts (such as peanut, hazelnut, and almond), and various house dust mites (D. pteronyssinus, D. farinae, and B. tropicalis). These findings align with prior studies suggesting that cross-reactivity is more likely among allergens with structural homology or those belonging to the same botanical or zoological families [27, 28]. Such co-sensitization patterns may be attributed to shared allergenic components, including profilins, tropomyosins, and other conserved protein families. The phenomenon of molecular mimicry, where structurally similar epitopes are recognized by the same IgE antibodies, may also contribute to the observed correlations [29, 30]. These insights hold important clinical implications: patients sensitized to one allergen may develop reactions to related allergens, even without direct exposure, complicating both diagnosis and management. However, the presence of co-sensitization does not necessarily indicate clinical allergy, and the connection between sensitization profiles and actual symptoms remains complex and not yet fully understood. Further molecular and immunological research is needed to clarify the mechanisms underlying cross-sensitization and to determine how patterns translate into clinical expression. In particular, a deeper understanding of co-sensitization in the pathophysiology of AD could support more precise diagnostic strategies and personalized therapeutic interventions.

The AD group showed a significantly higher overall sensitization rate compared to the non-allergic group, particularly in cases of polysensitization. This highlights a strong association between AD and increased allergic sensitization. The relatively high rate of house dust mite sensitization observed in the control group may reflect the high background prevalence of house dust mite sensitization in Asian populations. Notably, prior studies conducted in Vietnam [11] and Shanghai [10] in patients with urticaria, a non-atopic condition with minimal association with house dust mites, have similarly reported non-negligible sensitization rates. Patients with AD were more frequently sensitized to multiple allergen groups, including food-derived antigens (e.g., rice grain, barley flour, corn grain, egg yolk, egg white, peanut, wheat flour, oat flour, rye flour, apple, shrimp/prawn, soybean, and orange); fungal and yeast allergens (C.albicans, Baker’s yeast, Brewer’s yeast, and A. alternata); house dust mites (D. farinae and D. pteronyssinus); and animal dander (cat and dog). Atopy is a genetically determined predisposition to develop allergic hypersensitivity reactions, characterized by an exaggerated immune response to common environmental allergens, leading to elevated production of IgE [31]. When evaluating the role of individual allergens in AD specifically, or in atopic diseases in general, sensitization to certain allergens may play a more significant role in pathogenesis than others. The findings from our study suggest that some allergens may have greater pathogenic relevance in AD. These results are also consistent with previous research, including a cohort study of 400 young children with AD, which showed that sensitivity to peanuts, eggs, cats, or dogs was associated with more severe disease and impaired skin barrier function [32]. Food allergies to rice grain, cereals, and nuts are rare among the Vietnamese population; however, sensitization to these allergens may serve as a marker of atopic status. Previous studies have also suggested that these allergens may be associated with the severity of atopic diseases [33]. Conversely, although sensitization to cow’s milk, goat’s milk, and beef was also prevalent in the AD group, these differences did not reach statistical significance compared to the non-allergic group. This finding suggests that the immunologic impact of milk allergens in the pathogenesis of AD may be less pronounced than that of house dust mites, eggs, and other selected allergens. Our study showed that the group without allergic diseases also had a considerable proportion of individuals sensitized to respiratory allergens, while conversely, a proportion of patients with AD were not sensitized. This suggests that the definition of atopic diseases may need to be reconsidered. IgE plays only a partial role in the pathogenesis of atopic conditions. Recent studies have increasingly highlighted the importance of barrier dysfunction in these diseases [34, 35]. Atopic conditions are likely to develop through the combined effects of a genetic predisposition to IgE production and barrier impairment.

Our study supports the hypothesis that patients with AD who are sensitized to airborne allergens –such as house dust mites, animal dander, and certain molds – are at an increased risk of developing respiratory allergic diseases, notably asthma and allergic rhinitis. These findings are consistent with previous studies conducted in Italy [36] and the Czech Republic [37]. Our study demonstrated a high prevalence of sensitization to several allergens, including C. albicans, D. farinae, D. pteronyssinus, rice grain, barley flour, rye flour, dog dander, and cat dander. These allergens showed significantly higher sensitization rates in patients with AD compared to the control group. Moreover, patients with AD who were sensitized to these allergens were more likely to be co-sensitized to aeroallergens. Recent studies have also shown that certain allergens play a more prominent role in the development of asthma and/or allergic rhinitis [38, 39]. In addition, patients with atopy frequently exhibit high rates of polysensitization; therefore, sensitization patterns may need to be analyzed according to allergen interaction patterns [38, 40]. These findings highlight the potential role of these specific allergens not only in the pathogenesis of AD but also in the broader context of atopic disease development. Recent studies have demonstrated that epidermal barrier dysfunction plays a key role in allergen sensitization and the development of atopic diseases. Since AD is considered the starting point of the atopic march, it should be the primary focus of strategies for allergy prevention [41]. These findings underscore the importance of early interventions for patients with AD who are sensitized to aeroallergens. Strategies such as allergen avoidance or immunotherapy may provide benefits not only in managing current symptoms but also in preventing the progression to other atopic conditions, such as asthma or allergic rhinitis, later in life. However, further research with larger sample sizes is needed to confirm these associations and to gain a deeper understanding of the molecular mechanisms underlying this relationship.

This study provides the first large-scale assessment of allergen sensitization patterns in Vietnamese patients with atopic AD. Sensitization profiling, particularly to airborne allergens, may aid risk stratification and identification of comorbid respiratory allergic diseases. Our findings highlight the key role of house dust mite sensitization in atopic diseases in Vietnam, consistent with evidence that allergen immunotherapy can reduce AD severity [5]. Current guidelines support allergen immunotherapy with respiratory allergens in patients with moderate to severe AD, mainly in those aged ≥5 years [3].

This study presents several limitations that warrant consideration. First, the sample size was relatively small and drawn from a single center, which may limit the generalizability of the findings. Second, allergic disease diagnosis was based upon clinical diagnosis and not on objective criteria. In addition, skin prick testing was not performed, and molecular allergology (component-resolved diagnostics) was not available; therefore, the clinical relevance of the observed IgE sensitizations could not be confirmed. Third, we cannot exclude passive IgE binding in those samples with very high IgE levels. Additionally, because of the retrospective design, information on AD severity, including validated scoring systems (e.g., SCORAD, EASI, or IGA), was not available, which limited our ability to assess the association between disease severity and sensitization patterns. Information on disease-related treatments, including biologics, topical corticosteroids, and allergen immunotherapy, together with treatment responses, was not available, which constitutes an additional limitation of this study.

Conclusion

Patients with AD exhibit elevated sensitization rates to both food and airborne allergens. In this Vietnamese cohort, house dust mites, egg whites, cow’s milk, and almonds were identified as the most prevalent allergens among AD patients. Sensitization patterns differed across age-groups. High sensitization rates do not necessarily indicate clinical relevance; therefore, results should be interpreted with caution, and clinical correlation is essential to guide management and avoid unnecessary dietary or avoidance measures. Notably, patients with AD showed significantly higher sensitization rates to C. albicans, D. pteronyssinus, D. farinae, cat dander, dog dander, rice grain, barley flour, and rye flour compared to individuals with no allergic diseases. Furthermore, sensitization to these allergens in AD patients was associated with an increased risk of comorbid respiratory allergic conditions. This distinctive sensitization profile may serve as a potential biomarker of atopy. These findings highlight the importance of early diagnosis and the implementation of targeted management strategies in children with AD.

Acknowledgments

The authors express their sincere gratitude to all participants, specialists, physicians, and researchers who contributed to the data collection for this study. We are grateful to the patients and their families for their trust and valuable cooperation during diagnosis, treatment, and participation in this study.

Statement of Ethics

This study was approved by the Human Research Ethics Committee of the Vinmec Healthcare System (Approval No. 81/2023/CN/HĐĐĐ VMEC). The requirement for written informed consent was waived by the same Ethics Committee because of the retrospective nature of the study and the use of existing medical records with anonymized data. All procedures involving human participants were conducted in accordance with the ethical standards of the responsible institutional committee and with the World Medical Association Declaration of Helsinki.

Conflict of Interest Statement

All authors declare no conflicts of interest.

Funding Sources

No specific grant from any funding agency in the public, commercial, or not-for-profit sectors was received for this research.

Author Contributions

Duy-Bo Nguyen designed the study and data analysis and wrote the manuscript. Thanh Huyen Thuc, Ha Phuong VO, Thi Mai Vu, Thi Hai Yen Pham, Quynh Anh Nguyen, Thi Minh Huong LE, Van Dinh Nguyen, and Duy-Bo Nguyen diagnosed patients and data collected. Quynh Trang Tran and Thanh Nguyen Phan performed total and specific IgE testing and data collected. Thanh Huyen Thuc, Timothy Craig, Sheryl Van Nunen, Chi Hieu Chu, and Thi Minh Nguyet Nguyen discussed the results and reviewed the manuscript. Le Nam Nguyen, Nhat Tan Tran, and Van Hien Dam performed data analysis and made the figures and tables. Van Dinh Nguyen anh Anh-Tuan Dinh-Xuan designed the study, discussed the results, and reviewed the final version.

Funding Statement

No specific grant from any funding agency in the public, commercial, or not-for-profit sectors was received for this research.

Data Availability Statement

The data that support the findings of this study are not publicly available due to privacy and ethical restrictions related to patient data but are available from the corresponding author upon reasonable request.