[Prevalence of sensitization of Japanese cedar pollen in children from infancy to adolescence].

BACKGROUND: In Japan, morbidity of Japanese cedar pollinosis has dramatically increased, especially in children. However, little is known about the prevalence of pollinosis and sensitization to Japanese cedar pollen (JCP) in young children. OBJECTIVE: The aim of this study is to investigate the prevalence of sensitization to JCP in allergic and non-allergic children from infancy to adolescence. METHODS: Two hundred forty three children with allergic diseases (age 8 months-16 years, mean 5 years) and 137 children without allergic diseases (age 1 month-15 years, mean 4 years) were recruited. Their specific IgE to JCP, house dust mite, orchard grass pollen, egg white, and milk were measured with the CAP-RAST system. A questionnaire was filled out by their parents. RESULTS: The percentage of positive (> or = 2) CAP-RAST to JCP was 47.1% in children with allergic diseases and 19.9% in children without allergic diseases. In children with allergic diseases, the ratio had risen rapidly from 3 to 5 years old. In children without allergic diseases, the ratio of JCP sensitization has gradually increased from the infancy to adolescence. The youngest child who had been sensitized to JCP was 23-month-old boy with atopic dermatitis. The proportion of children who were born from January to march was significantly higher in JCP sensitized group than JCP non-sensitized group. The ratio of house dust mite and orchard grass pollen sensitization was higher in JCP sensitized group than those in JCP non-sensitized group. CONCLUSION: Large number of children acquire sensitization to JCP in their preschool age. We need to develop the way how to protect JCP sensitization in the early stage of life.

[A questionnaire survey of asthma in children with co-morbid allergic rhinitis].

BACKGROUND: Bronchial asthma is often complicated with allergic rhinitis (AR). OBJECTIVE: To investigate the relationship between the upper and lower airway diseases in children with asthma, we performed a questionnaire survey at 6 centers in Kinki area in Japan. METHODS: A questionnaire was filled out by parents of 333 asthmatic children (0-16 years, median age 7). It included questions concerning nasal symptoms, onset ages of rhinitis and asthma, correlation between nasal symptoms and asthma symptoms, and family history of allergic diseases. RESULTS: One hundred and fifty five (46.5%) subjects answered to have any nasal diseases; 20 with sinusitis, 46 with seasonal AR, and 119 (35.7%) with perennial AR. To further clarify the relationship of asthma and concomitant AR, we focused on patients with perennial AR and compared the clinical characteristics with patients with no nasal diseases. Percentage of non-atopic asthma was significantly lower in patients with comorbid AR than those without. Severity of asthma tended to be milder and family history of perennial AR was more often in the former than the latter group. Interestingly, asthmatic children with comorbid AR were more likely to have cold air-induced asthma exacerbations. In the subjects with comorbid AR, concomitant exacerbation of the upper and lower airways occurred in 38.7%. The median age of onset of asthma and nasal symptoms was 2 and 4 years, respectively. In 43.9% of them, upper airway symptoms started either before or simultaneously with asthma. CONCLUSION: The attention should be paid to the nasal symptoms in children with asthma, especially they have atopic asthma and positive family history of perennial allergic rhinitis. It is important that an appropriate diagnosis and treatment of nasal symptoms to better control asthma in children.