Objective: To assess the correlations between Immunoglobulin E (IgE) levels, pruritus, and lesion severity in patients with eczema, atopic dermatitis, or urticaria.
Methods: A retrospective study was conducted and data of 814 patients who visited the dermatology or allergy clinics of multiple hospitals, from December 2019 to December 2021, were collected. Patients were divided into children group (< 18 years, 325 cases), adult group (18– 60 years, 435 cases), and older population group (> 60 years, 54 cases) based on the age. Baseline information, pruritus severity, severity of skin lesions, total IgE level, and specific IgE level were recorded to analyze the complex relationship between them.
Results: The prevalence of allergic conjunctivitis and allergic rhinitis in the children group was significantly higher than that in the adult and older population group (P < 0.01 or P < 0.05). The positive rate of specific IgE in children group was significantly higher than that in the adult and older population group (P < 0.01). The IgE levels in children with moderate pruritus were significantly lower than those of severe pruritus (63.39vs 114.42 IU/mL, P < 0.05). The IgE levels in children with mild and moderate skin lesions were significantly lower than those in children with severe skin lesions (58.95 vs 72.88 vs 169.15 IU/mL, P < 0.001 or P < 0.01, respectively).
Conclusion: Relationships among age, severity of skin pruritus and lesions, and allergen-specific IgE response are complex and subtle, displaying dynamic patterns.

Keywords: multi-center analysis, immunoglobulin E, pruritus severity, lesion severity