Clinical Characteristics of Infants Under Two Years of Age with Early Sensitization to House Dust Mites

<b>Background:</b> Early-life sensitization to house dust mites (HDMs) is a recognized risk factor for adverse respiratory allergic outcomes. <b>Methods:</b> We investigated the clinical characteristics of infants under two years of age who visited our allergy clinic for evaluation with detectable HDM-specific IgE (sIgE) and compared them to HDM-sIgE-negative infants. <b>Results:</b> Among 1793 infants tested for HDM sIgE, 96 (5.4%) demonstrated sensitization. In the HDM-positive cohort, the prevalence of atopic dermatitis was 74.0% (90.9% among those <12 months), food allergy was 57.3% (100% among those <12 months), egg white sensitization was 71.9% (90.9% among those <12 months), and cow's milk sensitization was 56.3% (81.8% among those <12 months). Atopic dermatitis, food allergy, ≥4 wheezing episodes, physician-diagnosed asthma, allergic rhinitis, egg white sensitization, cow's milk sensitization, and sensitization to three or more food allergens were significantly more common in the HDM-positive group compared with the HDM-negative group. Significant correlations were observed between HDM sIgE and total IgE levels, as well as between HDM sIgE and egg white sIgE levels. Overall, HDM sensitization in infants was most frequently accompanied by atopic dermatitis and egg white sensitization. <b>Conclusions:</b> These findings suggest that early HDM sensitization should be closely monitored, particularly in infants with atopic dermatitis and food allergies who exhibit elevated total IgE and egg white sIgE levels.