[Analysis of allergen sensitization profiles in patients with skin diseases at a hospital in Shanghai City from 2023 to 2024].

To investigate the differences in allergen-specific immunoglobulin E (specific immunoglobulin E, sIgE) profiles and levels between patients with allergic and non-allergic skin diseases, a single-center retrospective cross-sectional study was conducted. Adult patients who visited Shanghai Skin Disease Hospital between May 2023 and June 2024 and underwent quantitative sIgE testing were included. A total of 10 184 patients were analyzed, including 8 564 patients with allergic skin diseases and 1 620 patients with non-allergic skin diseases. The χ² test was used to compare the differences in sIgE-positive allergen categories between the two groups. The Mann-Whitney U test was applied to compare sIgE levels, and the Kruskal-Wallis test was used to further analyze sIgE elevation among different types of allergic and non-allergic skin diseases. Logistic regression analysis was performed to assess the effect of sex on sIgE positivity. The overall sIgE positivity rate among patients with allergic skin diseases was 87.07% (7 457/8 564). Among them, the positivity rate for inhalant allergens was 75.43% (6 460/8 564), with dust mites, house dust mites, and tropical mites being the most common. The positivity rate for food allergens was 66.83% (5 723/8 564), with almond, shrimp, and soybean ranking highest. In patients with non-allergic skin diseases, the overall sIgE positivity rate was 46.17% (748/1 620). The positivity rate for inhalant allergens was 45.62% (739/1 620), mainly tropical mites, house dust, and house dust mites, while the positivity rate for food allergens was 41.91% (679/1 620), with almond, shrimp, and soybean being the most frequent. The majority of allergens showed higher sIgE positivity rates in allergic skin diseases than in non-allergic skin diseases. Quantitative analysis of sIgE-positive patients demonstrated that sIgE levels for most allergens were significantly higher in patients with allergic skin diseases than in those with non-allergic skin diseases; however, sIgE levels for Alternaria alternata (Z=4.10, P<0.001), milk (Z=3.36, P=0.01), and egg white (Z=1.42, P=0.04) were significantly higher in patients with non-allergic skin diseases. Sex-stratified analysis revealed that female patients with non-allergic skin diseases had a significantly higher sIgE positivity rate than male patients (χ²=81.38, P<0.001), whereas no significant sex difference was observed among patients with allergic skin diseases (χ²=0.05, P>0.05). Logistic regression analysis indicated that sex was an important factor associated with sIgE positivity in non-allergic skin diseases (OR=3.02, 95%CI=2.53-3.61, P=0.01), but not in allergic skin diseases (OR=1.15, 95%CI=1.01-1.30, P>0.05). In conclusion, abnormal allergen-specific sIgE is not only prevalent in patients with allergic skin diseases but is also detectable in patients with non-allergic skin diseases, with significant sex-related differences observed in the latter. Expanding the spectrum of sIgE testing may contribute to the precision diagnosis and management of allergic skin diseases, meanwhile the clinical significance of sIgE abnormalities in non-allergic skin diseases warrants further investigation.