Analysis of the results of specific IgE detection for cat and dog dander allergens in 141, 165 tests with allergic diseases

Abstract

Objective

The incidence of pet allergies continues to rise. This study investigates the clinical distribution characteristics and changes of cat and dog dander allergens among all outpatients and inpatients treated at Hangzhou First People’s Hospital from 2016 to 2024. It aims to provide data support for clinical allergen screening, individualized avoidance strategies, and precision diagnosis and treatment.

Methods

A retrospective cohort study was conducted. All outpatients and inpatients who underwent serum allergen-specific IgE (sIgE) antibody testing at Hangzhou First People’s Hospital from January 2016 to December 2024 were retrospectively included. The study analyzed each test individually, repeated tests performed at different time points for the same patient were included in the analysis. The characteristics and trends of cat and dog dander allergens were analyzed over a nearly 9-year period, encompassing a total of 141,165 test instances. Male cases numbered 70,904 (50.23%), while female cases numbered 70,261 (49.77%). Patients were categorized by age group: 0–3 years (infant group, 6,729 cases, 4.76%), 4–12 years (child group), 13–18 years (adolescent group), 19–65 years (adult group), and > 65 years (elderly group). This yielded 20,197 cases (14.31%) in the infant group, 55,280 cases (39.16%) in the child group, 6,729 cases (4.76%) in the adolescent group, 54,345 cases (38.50%) in the adult group, and 4,613 cases (3.27%) in the elderly group. Statistical analysis employed the χ² test.

Results

Among 141,165 test results, the sIgE positivity rate for cat dander allergen (3.76%) was higher than that for dog dander allergen (3.38%), with a statistically significant difference (χ²=11680.12, P < 0.001). The positive rates for cat dander sIgE from 2016 to 2024 were 1.45%, 0.64%, 0.66%, 1.74%, 2.54%, 4.37%, 5.66%, 6.74%, and 9.36%, respectively. The positive rates for dog dander allergen sIgE sensitization from 2016 to 2024 were 0.57%, 0.16%, 0.09%, 0.25%, 0.50%, 3.30%, 5.77%, 7.09%, and 11.48%, respectively; Since 2018, the positive rates for cat and dog dander allergen sIgE have shown a significant upward trend over time in both males and females. The positive rates for cat and dog dander allergen sIgE were consistently higher in males than in females, with statistically significant differences (χ² = 11.922, χ² = 67.499, p < 0.05). The positive rates for cat dander allergens (3.94%, 3.59%) were significantly higher than those for dog dander allergens (3.78%, 2.99%) in both males and females, with statistically significant differences (χ²=5121.29, χ²=6755.70, P < 0.001); The positive rates for cat dander allergens in the infant/child group (2.30%) and elderly group (0.59%) were significantly lower than those for dog dander allergens (4.05%, 0.89%), with both differences being statistically significant (χ²=615.55, χ²=55.43, P < 0.001); The positive rates for cat dander allergens in the children, adolescents, and adults groups (4.78%, 6.54%, 3.18%) were significantly higher than the dog dander allergen positive rates (4.75%, 4.64%, 1.81%), with all differences being statistically significant (χ²=2429.89, χ²=369.45, χ²=1191.82, P<0.001); The concordance rate for cat and dog dander allergies was 68.06%, with moderate correlations observed between sIgE levels for these allergens. When only one allergen showed positive sIgE, most positive results were low-level (levels 1–3); however, combined high-level positives also occurred.

Conclusion

This study reveals the epidemiological characteristics of cat and dog dander allergens in Hangzhou over the past nine years, revealing patterns of overall increase, gender differences, and age clustering. These findings provide crucial data support for optimizing clinical allergen screening strategies, developing personalized avoidance plans, and advancing precision diagnosis and treatment.

Introduction

In recent years, the prevalence and incidence of allergic diseases has increased, attracting growing attention [1]. These diseases significantly impact patients’ quality of life, and their global prevalence has become one of the major public health challenges of the 21st century [2]. The pathogenesis of allergies is complex and relatively unclear. Genetic and environmental factors are key determinants of the occurrence and development of allergic diseases [3]. The treatment and prevention of allergic diseases largely depend on accurately identifying pathogenic allergens and avoiding exposure to them. As people’s economic levels continue to improve and urbanisation accelerates, more individuals are keeping pets, leading to an increase in people with pet al.lergies, such as to cats or dogs. In order to understand the distribution and changing trends of cat and dog dander allergens within the population of Hangzhou over the past nine years, this study retrospectively analysed the results of the detection of specific immunoglobulin E (sIgE) for cat and dog dander allergens in 141,165 patients between January 2016 and December 2024. This study aims to identify patterns of sIgE for cat and dog dander allergens through large-sample epidemiological analysis, systematically explore the sensitisation rules of these allergens and investigate cross-reactivity between sIgE of different allergens. The results are expected to provide data to support clinical allergen screening, the formulation of individualised avoidance plans and precise diagnosis and treatment. They will also provide a scientific basis for the development of public health policies related to pet feeding management and the prevention of allergic diseases.

Materials and methods

General data: A retrospective analysis was conducted on 143,971 test samples from patients with allergic diseases who visited the First People’s Hospital in Hangzhou between January 2016 and December 2024. After excluding cases with incomplete data, a total of 141,165 suspected allergic samples that had undergone sIgE testing for cat and dog dander allergens were included in this study. The study was based on test instances rather than individual patients, as the same patient may have been tested repeatedly at different time points. Of these test instances, 70,904 (50.23%) were male and 70,261 (49.77%) were female, with a male-to-female ratio close to 1:1. The age range was 0–99 years, with an average age of (20.47 ± 19.58) years. Patients were categorised into five groups based on age: infants (0–3 years), children (4–12 years), adolescents (13–18 years), adults (19–65 years) and elderly people (> 65 years). The primary clinical manifestations among the 141,165 patients included respiratory symptoms, skin symptoms, and other conditions. (Table 1).

Table 1.

General clinical data of 141,165 patients

Basic Characteristics	Quantity( %)
Gender
Male	70,904(50.23%)
Female	70,261(49.77%)
Age Group
Infant Group (0–3 years)	20,197(14.31%)
Child Group (4–12 years)	55,280(39.16%)
Adolescent Group (13–18 years)	6729(4.76%)
Adult Group (19–65 years)	54,345(38.50%)
Elderly Group (> 65 years)	4613(3.27%)
Clinical Symptoms
Allergic rhinitis, sinusitis, epistaxis, etc.	65,536(46.43%)
Asthma, bronchitis, allergic cough, etc.	25,217(17.86%)
Allergic dermatitis, urticaria, eczema, etc.	25,142(17.81%)
Other	25,270(17.90%)

Test method

Collect 2–4 mL of venous blood from all patients. Centrifuge at 3500 rpm for 5 min to separate serum. The DX-Blot 45II fully automated immunoblotting instrument (Hangzhou Zheda Dixun Bio-Genetic Engineering Co., Ltd.), CanoScan 9000 F Mark II scanner (Canon Inc., Japan), and corresponding reagents were used to detect sIgE concentrations against cat and dog dander allergens in patient sera. Procedures strictly followed instrument and reagent manuals. Results were interpreted using semi-quantitative allergen analysis software (DiX-Plus V6.0). All testing was conducted in the same laboratory, using reagents and equipment from the same brand throughout. The testing platform did not change during the process. To ensure data comparability, the same sIgE grading standard was applied to all tests. Grading and interpretation followed internationally recognized sIgE concentration-to-grade standards [4]. The detection range was 0.35 IU/mL to 100 IU/mL; sIgE ≥ 0.35 IU/mL was considered positive. sIgE antibody concentrations were categorized into six levels: Level 0 (negative), Levels 1–6 (positive), with higher levels indicating stronger positivity. The classification is as follows: Level 0 (< 0.35 IU/mL), Level 1 (0.35–0.70 IU/mL), Level 2 (0.71–3.50 IU/mL), Level 3 (3.51–17.50 IU/mL), Level 4 (17.51–50.00 IU/mL), Level 5 (50.01–100.00 IU/mL), Level 6 (> 100.00 IU/mL).#x003C; 0.05 indicates statistically significant differences.

Statistical methods

Statistical analysis was performed using SPSS 23.0 and MedCalc 19.0 software. Count data, such as the positive rate of cat and dog dander allergens and the frequency of positive results, were presented as histograms and percentages. Intergroup comparisons were conducted using the chi-squared test, and effect sizes with 95% confidence intervals were reported. Non-normally distributed quantitative data were described using the median (interquartile range), denoted as M (Q1, Q3). Correlation coefficient analysis employed Pearson’s correlation coefficient test. Based on the absolute value of the correlation coefficient (|r|), correlations were categorised as follows: Low correlation: |r| ≤ 0.3,Moderate-low correlation: 0.3 ≤ |r| < 0.5, Moderate correlation: 0.5 ≤ |r| < 0.8,High correlation: 0.8 ≤ |r| < 1.0,Perfect correlation: |r| = 1.0 P < 0.05 indicates statistically significant differences.

Result

Distribution of positive rates for cat and dog dander allergens

Among 141,165 patients, the positive rates for cat and dog dander allergens sIgE were 3.76% (5,311/141,165) and 3.38% (4,778/141,165), respectively. Among the positive results for cat and dog dander, the distribution by severity level showed that level 2 (27.78%) was the most prevalent for cat dander allergens, with levels 2 and 3 combined accounting for 41.65%. For dog dander allergens, level 2 (24.75%) was the most common, while levels 1 and 2 accounted for 39.90%. The sIgE positivity rate for cat dander allergens (3.76%) was higher than for dog dander allergens (3.38%), with a statistically significant difference (χ² = 11,680.12, p < 0.001) (Fig. 1).

Fig. 1.

Distribution of positive rates for cat and dog dander allergens

Trend in positive rates for cat and dog dander allergens and annual gender differences in positive rates for cat and dog dander allergens among males and females

The sIgE positive rates for cat dander allergens were 1.45%, 0.64%, 0.66%, 1.74%, 2.54%, 4.37%, 5.66%, 6.74% and 9.36% respectively from 2016 to 2024. Since 2017, there has been a significant upward trend in the sIgE positive rate for cat dander allergens. The positive rates for dog dander allergen sIgE sensitisation from 2016 to 2024 were 0.57%, 0.16%, 0.09%, 0.25%, 0.50%, 3.30%, 5.77%, 7.09% and 11.48% respectively. Since 2018, the sIgE positive rate for dog dander has shown a significant upward trend. For both genders, the sIgE positive rates for cat and dog dander allergens have increased significantly in absolute numbers and percentages since 2018 (Fig. 2). Except for statistically significant gender differences in cat dander sIgE positive rates in 2019 and 2021, no such differences were observed in other years. Statistically significant gender differences in dog dander sIgE positive rates were noted in 2017, 2022, 2023 and 2024, with no differences observed in other years. Of the 141,165 test results, males exhibited higher sIgE positive rates to both cat and dog dander allergens than females. χ² values of 11.922 and 67.499, respectively, indicate statistically significant differences. However, an analysis of effect sizes revealed that the actual magnitude of these gender differences was small (cat: φ = 0.009; dog: φ = 0.022). The 95% confidence intervals for the difference in positive rates were also narrow (cat: 0.16–0.54%; dog: 0.54–1.04%). This suggests that, while statistically significant, these differences may have limited clinical or practical significance. (p < 0.05; Table 2).

Fig. 2.

Trends in allergen positive rates for cat and dog dander by gender

Table 2.

Differences in positive rates for cat and dog dander allergens by gender over the years

Year	Positive count of cat dander		χ²	p	Positive count of dog dander		χ²	p
	Female(%)	Male(%)			Female(%)	Male(%)
2016	87 (1.49%)	89 (1.42%)	0.104	0.403	37 (0.63%)	32 (0.51%)	0.809	0.218
2017	37 (0.54%)	54 (0.74%)	2.220	0.083	6 (0.09%)	17 (0.23%)	4.609	0.025
2018	57 (0.57%)	72 (0.75%)	2.510	0.067	13 (0.13%)	5 (0.05%)	3.206	0.058
2019	135 (1.47%)	173 (2.04%)	8.566	0.002	25 (0.27%)	20 (0.24%)	0.217	0.376
2020	146 (2.45%)	163 (2.62%)	0.342	0.299	25 (0.42%)	36 (0.58%)	1.534	0.133
2021	307 (3.99%)	382 (4.73%)	5.155	0.013	239 (3.11%)	282 (3.49%)	1.829	0.095
2022	460 (5.62%)	483 (5.72%)	0.071	0.408	407 (4.97%)	552 (6.53%)	18.609	0.000
2023	529 (6.65%)	548 (6.83%)	0.199	0.339	486 (6.11%)	647 (8.06%)	23.088	0.000
2024	762 (8.96%)	828 (9.77%)	3.330	0.360	861 (10.12%)	1088 (12.84%)	30.934	0.000
Total	2520(3.59%)	2792(3.94%)	11.922	0.000	2099 (2.99%)	2679 (3.78%)	67.499	0.000

Differences in the distribution of positive rates for cat and dog dander allergens across gender and age groups

Results of an analysis of differences in the distribution of cat and dog dander allergen sensitisation across different genders and age groups indicate that the positive rates for cat dander allergens (3.94%, 3.59%) were significantly higher than those for dog dander allergens (3.78%, 2.99%) in both males and females, with statistically significant differences (χ² = 5,121.29, χ² = 6,755.70, p < 0.001). In the infant and child group, the positivity rate for cat dander allergens (2.30%) was significantly lower than that for dog dander allergens (4.05%), with a statistically significant difference (χ² = 615.55, p < 0.001). In the children group, the positivity rate for cat dander allergens (4.78%) was significantly higher than that for dog dander allergens (4.75%), with a statistically significant difference (χ² = 2429.89, p < 0.001). In the adolescent group, the positivity rate for cat dander allergens (6.54%) was significantly higher than that for dog dander allergens (4.64%), with a statistically significant difference (χ² = 369.45, p < 0.001). The positive rate for cat dander allergens (3.18%) was significantly higher than that for dog dander allergens (1.81%) in the adult group, with a statistically significant difference(χ²=1191.82, P < 0.001). The positive rate for cat dander allergens in the elderly group (0.59%) was significantly lower than that for dog dander allergens(0.89%), with a statistically significant difference (χ²=55.43, P < 0.001) (Table 3).

Table 3.

Differences in the distribution of positive rates for cat and dog dander allergens across gender and age groups

Project	Cat dander allergen			Dog dander allergen			χ²	p
	Negative(n)	Positive(n)	Positive rate(%)	Negative(n)	Positive(n)	Positive rate(%)
Male	68,112	2792	3.94%	68,225	2679	3.78%	5121.29	0.000
Female	67,741	2520	3.59%	68,162	2099	2.99%	6755.70	0.000
Infant	19,724	473	2.30%	19,379	818	4.05%	615.55	0.000
Child	52,635	2645	4.78%	52,655	2624	4.75%	2429.89	0.000
Adolescent	6289	440	6.54%	6417	312	4.64%	369.45	0.000
Adult	52,619	1726	3.18%	53,363	983	1.81%	1191.82	0.000
Elderly	4586	27	0.59%	4572	41	0.89%	55.43	0.000

Co-sensitisation to cat and dog dander allergens

Of 141,165 patients, 8,512 tested positive for specific IgE (sIgE) to cat or dog dander allergens. More specifically, 5,311 cases tested positive for cat dander sIgE and 4,778 for dog dander sIgE. There was a 68.06% concordance rate between cat and dog dander allergens, Spearman’s correlation coefficient was used to analyse the correlation between cat and dog dander sIgE, yielding a value of r = 0.6863. This indicates a moderate correlation between specific IgE antibodies to cat and dog dander allergens, Most positive results when only one allergen showed positive sIgE were concentrated at low levels (levels 1–3); however, combined high-level positivity also occurred (Table 4).

Table 4.

Co-sensitization to cat and dog dander allergens

Cat dander	Dog dander							r
	Level 0	Level 1	Level 2	Level 3	Level 4	Level 5	Level 6
Level 0	0	1038	1497	321	132	69	144	0.6863
Level 1	480	53	126	24	6	3	9
Level 2	1770	114	264	112	43	22	40
Level 3	849	47	114	89	34	20	27
Level 4	336	19	58	35	24	9	25
Level 5	158	8	23	27	20	14	21
Level 6	141	10	25	26	20	22	44

Discussion

Allergic diseases are conditions triggered by allergen exposure, predominantly mediated by IgE. Primary types include respiratory allergic reactions, skin allergic reactions, and anaphylactic shock. While anaphylactic shock occurs less frequently than respiratory or skin allergic reactions, it can be life-threatening when it occurs. Accurate allergen identification is essential for selecting the most effective treatment strategies. In vitro detection of serum-specific Immunoglobulin E (sIgE) is a key method for identifying allergens. Fur-bearing animal allergens are a significant source of indoor allergens and are a primary risk factor for airway allergic diseases [5–7]. In recent years, allergies to cat and dog dander have received more attention [8]. Analyzing the allergens in cat and dog dander in the Hangzhou region can help with the screening, diagnosis, and treatment of allergic diseases caused by these allergens.

This study analyzed the results of serum-specific IgE (sIgE) tests for cat and dog dander allergens in 141,165 cases. The sIgE positive rates for cat dander allergens was 3.76% (5,311/141,165), while that for dog dander allergens was 3.38% (4,778/141,165). The prevalence of positive sIgE for cat dander allergens (3.76%) was higher than that for dog dander allergens (3.38%). This finding is consistent with most domestic and international studies. However, Chen Yanlei et al. [9]. found that the positive rate for cat dander was significantly higher than that for dog dander (11.8% vs. 6.0%). In Guangzhou, China, the sIgE positive rates for cat and dog dander allergens were 5.78% and 4.62%, respectively [10]. A 2005–2006 nationwide U.S. survey reported an sIgE positive rates of 15.7% for pet dander (cat or dog), with cat dander allergy at 12.1% and dog dander allergy at 11.8% [11]. Level 2 represents the peak range for both cat and dog dander allergen positive rates. Cat dander reached 27.78%, while dog dander reached 24.75%. These rates are significantly higher than those of other levels. Level 1: “Dog dander %” (15.14%) was significantly higher than “Cat dander %” (8.24%). Level 3: “Cat dander %” (13.86%) was significantly higher than “Dog dander %” (7.45%). The proportion of positive reactions to cat and dog dander varied across the levels. From level 4 to level 6, the positive rates for both types of dander decreased significantly, indicating predominantly low concentrations of sIgE antibodies to cat and dog dander allergens. This finding is consistent with the results reported by Huang, Zhi-Feng, et al. [10]. Both this study and previous research have found significantly higher positive rates for cat dander than for dog dander. Possible reasons include: (1) cats frequently reside in bedrooms and on beds, increasing human exposure to allergens; (2) The primary allergenic proteins in cats have a low molecular weight (approximately 18 kDa) and are highly stable. They readily spread through the air and adhere to clothing and furniture surfaces. These particles persist in the environment long-term, entering small airways more easily and triggering allergic reactions such as asthma [12]; Third, dogs share a microbiome more closely aligned with humans, which contributes to human microbial diversity. In contrast, cat hair lacks this effect [13]. Coelho et al. assessed dog gut microbiomes and identified significant genetic similarities with human gut microbes. This likely explains the higher cat hair positivity rate observed in this study.

Close contact between infants and children and pets, such as cats and dogs, generally results in higher positive rates for cat and dog dander allergies compared to other inhalant allergens besides house dust mites/dust mites [14]. There was a persistent upward trend in positive rates for both cat and dog dander allergens (cat dander increased from 1.45% in 2016 to 9.36% in 2024, and dog dander rose from 0.57% to 11.48%). These findings align with those of most international studies. In the United States, for example, the prevalence of positive animal dander tests increased from 16.5% to 28.6% over the course of a decade, at an annual rate of 1.3% [11]. In Europe, cat dander allergies increased from 8.8% to 26.0% [15]. A 10-year Korean study found rising positive rates for both cat and dog dander among children [16]. Around 2016–2020, this study observed that all curves representing “cat/dog dander positive rates” remained stable at low levels, with most rates staying relatively low. From 2020 to 2024, all curves simultaneously showed a sharp increase. By 2024, most curves had approached or exceeded 12.5%, indicating explosive growth in positive rates for cat and dog dander allergens in recent years. This trend may be associated with increased pet ownership rates, accelerated urbanization leading to reduced exposure to natural environments, and greater frequency of human-pet contact (e.g., pets entering public spaces and cohabitation within households). An online survey of 22 countries revealed that approximately one-quarter of households worldwide have cats, and one-third have dogs [17]. Interacting with these animals may trigger allergic reactions due to exposure to pet dander and secretions. The study found that the positive rate for dander from different genders and pet types follows a pattern of “initial decline/stability → later surge.” This suggests that the risk of becoming sensitized to cat and dog dander allergens varies over time for the entire population (with no significant divergence in trends based on gender or pet type) and has increased significantly in recent years. According to the 2025 China Pet Industry White Paper, the total number of urban dogs and cats exceeded 120 million in 2024, marking a 2.1% increase from 2023. Since 2018, the pet cat population has grown rapidly, nearly doubling cumulatively. Together with the results of this study, this indirectly suggests that the sharp rise in cats and dogs has increased the probability of allergen exposure. Although this study did not collect pet ownership data directly, existing epidemiological information suggests that increased exposure to pets may be one environmental factor contributing to higher susceptibility rates. Further exposure-response studies are required to confirm this association.

This study identified differences in positive sensitization rates to cat and dog dander allergens among different age groups. The age trend for cat dander allergen positivity showed an initial increase, followed by a decline with advancing age. The percentages were as follows: adolescents (6.54%), children (4.78%), infants/toddlers (2.30%), adults (3.18%), and the elderly (0.59%). Sensitivity to cat dander peaked during adolescence and was lowest in the elderly. The age trend for dog dander allergen positivity showed an overall decline with increasing age: infant group (4.05%) ≈ child group (4.75%) > adolescent group (4.64%) > adult group (1.81%) > elderly group (0.89%). Similar to a previous domestic study, the results for cat dander sensitization were consistent, while those for dog dander were inconsistent. Children exhibited a higher positive rate for cat dander allergens than adults did, while the positive rate for dog dander allergens was lower. Adolescents and young adults exhibited the highest positive detection rates for both dog and cat allergens [18]. This study found relatively high sensitization to dog dander in infants and children, with a rapid decline in adulthood and maintenance of low levels in the elderly. Age- and species-specific patterns emerged for sensitization to cat and dog dander. Age dimension: Cat sensitization peaks in adolescence and drops sharply in old age, while dog sensitization remains relatively high in early childhood but declines rapidly in adulthood. Species dimension: Adolescents are more prone to cat sensitization, while infants and young children are more susceptible to dog sensitization. After adulthood, sensitization to both decreases, with a slightly lower rate for dogs than cats, reaching extremely low levels in the elderly. These age- and species-specific differences in sensitization reflect the complex interplay of immune system development, environmental exposure, and microbiome regulation. The heightened susceptibility to cats during adolescence likely stems from the combined effects of heightened immune activity and exposure intensity. The steep decline in susceptibility during old age may be associated with immune senescence and tolerance mechanisms. Additionally, this study found that the prevalence of sIgE positivity to cat/dog dander was 3.94%/3.78% in males and 3.59%/2.99% in females, with statistically significant differences. However, an analysis of effect sizes indicated that the actual magnitude of these gender differences was small (cat: φ = 0.009; dog: φ = 0.022). The 95% confidence intervals for the difference in positive rates were also narrow (cat: 0.16–0.54%; dog: 0.54–1.04%). This suggests that, while statistically significant differences exist, they may have limited clinical or practical significance. Further research is therefore needed to clarify the gender characteristics of sensitisation to cat and dog dander.

The Spearman correlation coefficient between cat and dog dander allergens was 0.6863, indicating a moderate correlation between sIgE responses to these allergens. This suggests a degree of cross-reactivity or shared exposure between the two allergens. The proteins found in cat and dog dander can explain the shared sensitization and monosensitization phenomena observed in cat and dog dander. However, this study did not use component-specific diagnostic techniques, so it was unable to distinguish between monosensitization and cross-reactivity. Integrating molecular allergen testing in the future may further elucidate the immunological mechanisms. Ohman et al. [19]. first identified the major sensitizing protein, Fel d 1, in cat dander in 1974. This protein rarely cross-reacts with other proteins, which explains the higher positive rate for cat dander compared to dog dander in this study. Seven major allergenic proteins have been identified in dogs [20], with Can f 1 and Can f 5 being the primary allergenic components [12]. Can f 1, 2, 4, and 6, like Fel d 4, belong to the lipoprotein family and exhibit highly similar tertiary structures due to homology within the lipocalin family [21]. This study found that, as allergen levels increased, the probability of co-sensitization rose synchronously, suggesting a potential synergistic effect in sensitization intensity between the two allergens. There were 3,734 co-sensitization cases involving dogs (level 0, non-sensitized) and cats (sensitized), exceeding the 3,201 cases involving cats (level 0, non-sensitized) and dogs (sensitized). This indicates that sensitization to cat dander is stronger than sensitization to dog dander. Combinations of cat/dog allergens with ≥ 4 sensitization levels were rare. “Single high sensitization while the other remains non-sensitized” was more common, and “multiple high sensitization” cases were even less frequent. These results suggest that exposure differences drive divergent sensitization outcomes and that repeated allergen stimulation increases the likelihood of developing “high sensitization.”

By analyzing allergen characteristics and trends over nearly nine years, this study provides valuable reference data for preventing and controlling clinical cat and dog dander allergies using big data analysis. However, several limitations exist. First, as a single-center retrospective analysis, regional bias may be present. Second, key confounding factors, such as pet ownership history and exposure frequency, were not collected, which precludes establishing definitive causal relationships. Third, sIgE testing method variations (e.g., reagent brands and cutoff value settings) may affect comparability of results, necessitating standardized testing procedures. Fourth, the analyzed data included positive rates per test instance, which may have included repeated tests for the same patient and caused discrepancies between the reported cat and dog dander allergen positive rates and actual prevalence.

In summary, this study systematically reveals the epidemiological characteristics of cat and dog dander allergens in Hangzhou over the past nine years. There has been a persistently rising positive rate, and males, children, and adults constitute high-risk groups. Cat dander shows slightly higher sensitization than dog dander, and there is a moderate correlation between the two. These findings provide crucial data to optimize clinical allergen screening strategies, develop personalized avoidance plans (e.g., adjusting pet exposure guidelines for different age groups), and advance precision diagnostics and treatment (e.g., selecting intervention methods based on sIgE titers). Further elucidating driving factors through future multi-center studies and environmental exposure analyses is necessary to provide scientific evidence for the prevention and control of pet-related allergic diseases.

Abbreviations

sIgE

serum allergen-specific IgE

Authors’ contributions

Yilin Li and Miaomiao Xu conducted research work, participated in data collection, and drafted the initial manuscript. They performed statistical analyses and contributed to the study design. Weihua Yang and Jing Li assisted in finalising the draft. All authors reviewed and approved the final version.

Funding

Research in this publication was supported by the Construction Fund of Key Medical Disciplines of Hangzhou (Clinical Research and Evaluation) under award number 2025HZGF04.

Data availability

The datasets used and analysed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

This study was conducted in accordance with the guidelines of the Declaration of Helsinki and received approval from the Ethics Review Committee of Hangzhou First People’s Hospital (Approval No.:2025ZN156-1 2025-05-22). We confirm that all data has been anonymised and is strictly confidential. Given the retrospective nature of this research, the Ethics Review Committee of Hangzhou First People’s Hospital has granted exemption from the requirement for informed consent.

Consent for publication

The publication has been approved by the Ethics Review Committee of Hangzhou First People’s Hospital.

Competing interests

The authors declare no competing interests.