Methods: A cross-sectional study was conducted on 629 children. Current allergic symptoms were assessed using the Korean-language ISAAC questionnaires adapted for preschool-aged children. The sensitization to five aero- and three food- allergens was evaluated by skin prick test.
Results: The prevalence of current asthma decreased (20.5%/8.2%), current rhinitis increased (36.1%/56.1%) with increasing age from 3 to 6 years, while no change in the prevalence of current eczema (16.9%/15.3%). Similarly, as age increased, sensitization rates to inhalant allergens increased (21%/33%), those to food allergens decreased (10%/2%). The prevalence of polysensitized children increased (8%/22%), monosensitized children decreased (18%/11%) with age, but atopic state did not change with age (27%/33%). The agreement rate between sensitization to dust mite and atopic state increased with age, showing a rate of 93% at 6 years (p=0.05). The presence of atopic dermatitis in the first 2 years of life (aOR=4.1, 2.2-7.6, P<0.001) and polysensitization (aOR=3.0, 1.4-5.0, P<0.005) were significant risk factors for current rhinoconjunctivitis. In contrast, monosensitization was a risk factor for current asthma (aOR=2.1, 1.1-4.1, P<0.024) and current eczema (aOR=2.1, 1.0-4.3, P<0.042).
Conclusions: These data showed that the type and numbers of sensitization and allergic symptoms changed with age in early childhood. Polysensitization may play an important role in allergic march.