[Recent pollen sensitization and its possible involvement in allergic diseases among children in a pediatric allergy...

We studied the rate of sensitization to several pollen allergens as well as to house dust mites in 226 children visiting our pediatric allergy clinic during the past 3 years (from April 1996 to March 1999). The allergens studied were Sugi (Japanese cedar pollen, Cryptomeria japonica), Kamogaya (Dactylis gromerata), Butakusa (ragweed, Ambrosia artemisiifolia), and Der f (house dust mite, Dermatophagoides farinae). The presence of nasal symptoms (either seasonal and perenial) was checked in 97 children visiting the clinic in March 1999. Overall average sensitization rates were 82.3% for Der f, 53.1% for Sugi, 38.5% for Kamogaya, and 17.1% for Butakusa. Among children aged 12 or more, sensitization rates for Sugi and Kamogaya were much higher (68.8%, 56.3%, respectively). Those who had seasonal nasal symptoms showed significantly higher rates of sensitization to the pollens. However, more than half of patients without nasal symptoms, 62.8% of whom had only atopic dermatitis (AD), also showed sensitization to the pollens. Several possible factors accounting for pollen sensitization in children with only AD and no sasal symptoms, such as existence of occult allergic rhinitis, future onset of allergic rhinitis, or pollen as directly aggravating factor of AD, need to be evaluated by careful follow-up of these cases.