Inhalant Allergen Sensitization: Prevalence, Risk Factors, and Geographic Variation in the USA

Abstract

Introduction: We aimed to assess the prevalence of IgE-mediated sensitization to two perennial (dust mite and animal) and four seasonal allergen sources (tree, grass, weed, and mold/fungi) using data from a national clinical reference laboratory (Quest Diagnostics).

Methods: Patients tested in 2019 for ≥1 specific serum IgE toward 4 dust mites, 14 animals, 32 trees, 12 grasses, 21 weeds, or 19 mold/fungi allergens were included. Patients with ≥1 specific IgE ≥0.10 kU/L within a source were considered sensitized for the source. Chi-square tests and multivariate logistic regression were used to compare the estimated prevalence of allergic sensitization related to demographics, geography, and clinical diagnosis.

Results: Sensitization for dust mite, animal, tree, grass, weed, and mold/fungi sources was 38.0% (21,161/55,735), 32.1% (21,888/68,035), 34.5% (22,975/66,567), 30.3% (21,664/71,575), 31.2% (22,960/73,605), and 19.7% (13,514/68,574), respectively. Across allergen sources, males had higher prevalence (from lowest to highest: 25.3% mold/fungi to 43.0% dust mite) compared to females (from lowest to highest: 16.1% mold/fungi to 34.6% dust mite); prevalence peaked in 10-19 years (from lowest to highest: 29.7% mold/fungi to 54.2% dust mite) and then decreased with increasing age; large metropolitan areas (from lowest to highest: 39.6% dust mite to 20.7% mold/fungi) had higher prevalence compared to small-to-medium metro (from lowest to highest: 36.6% dust mite to 17.9% mold/fungi) or nonmetro areas (from lowest to highest: 32.4% dust mite to 19.5% mold/fungi); a higher prevalence was observed in patients with asthma, atopic dermatitis, or rhinitis than in those with none of these diagnoses reported. Sensitization to perennial and seasonal allergens showed regional variation.

Conclusions: Prevalence of allergic sensitization to perennial and seasonal allergens is associated with patient age and sex, census regions, level of urbanization, and allergic disease states. These factors should be considered when designing and selecting allergen panels for diagnosing and treating symptomatic patients.

Keywords: Geography; Inhalant allergen; Risk factors; Seasonal allergen; Sensitization; USA.

Fig. 1.

Sensitization by gender and age, within a source. p value from chi-square test: all <0.0001.

Fig. 2.

Sensitization across 4 census regions within a source. p value from chi-square test: all <0.0001.

Fig. 3.

Sensitization by level of urbanization, within a source. p value from chi-square test: all <0.0001.

Fig. 4.

Sensitization by allergic disease state, within a source. p value from chi-square test: all <0.0001.

Fig. 5.

Adjusted odds ratios for independent predictors of allergic sensitization to at least one allergen with each allergen source (95% CI) by allergen source, in multivariate logistic regression (modeling sensitized vs. not sensitized).