A 13-year study of Japanese cedar pollinosis in Japanese schoolchildren.

BACKGROUND: Japanese cedar pollen (JCP) sensitization and Japanese cedar pollinosis (JCPS) appear to be increasingly prevalent in younger children. The present study investigated factors affecting JCP sensitization and JCPS development in school children. METHODS: In May or June each year from 1994 to 2006, 275-510 children were assessed for serum JCP-IgE and house dust mite (HDM)-IgE levels, and surveyed regarding rhinoconjunctival symptoms. RESULTS: Strong JCP sensitization (IgE > or = 17.5 U(A)/ml) was associated with age (odds ratio (OR) = 2.65), the amount of dispersed pollen in the observed year (OR = 2.03) and in the year following birth (OR = 1.51), the month of birth (OR = 2.18), and the recent birth cohort (OR = 1.96). Symptoms were negatively correlated with the recent birth cohort (OR = 0.69) after adjusting for JCP-IgE levels. Strong HDM sensitization was associated with gender (OR = 0.65 for girls) and the recent birth cohort (OR = 1.76). CONCLUSIONS: JCP sensitization appeared to be associated with the recent birth cohort and to increases in dispersed pollen just after birth and in the observed season. Although the recent birth cohort was more easily sensitized, they were not more likely to develop symptoms. In contrast to JCP sensitization, strong HDM sensitization appeared to develop prior to commencement of primary school and was more likely to affect boys.

Effects of polysaccharide derived from black currant on relieving clinical symptoms of Japanese cedar pollinosis: a randomized double-blind, placebo-controlled trial.

We investigated the efficacy of the polysaccharide derived from black currant, named cassis polysaccharide (CAPS), for inhibiting Japanese cedar pollinosis symptoms and improving quality of life by a randomized double-blind, placebo-controlled trial in 2006. A total of 28 subjects were enrolled in the study, and 10 subjects in each group completed the trial. Although there was no significant difference between the CAPS and placebo group in the weekly mean value of any symptom in the daily symptom diary at any time, a smaller degree of final symptom aggravation was found in the CAPS group. Significant aggravation of the score was finally observed in the placebo group with inferior conch swelling and with sneezing, itchy nose, itchy eye and watery eye in the Japan rhino-conjunctivitis quality of life questionnaire assessment, while the changes observed in the CAPS group were not significant. In conclusion, our findings clearly indicate that CAPS would be useful as a food supplement in assisting the treatment of Japanese cedar pollinosis.

[Clinical study of the paranasal sinuses of patients with Japanese Cedar pollinosis].

To clarify paranasal sinus change in patients with Japanese cedar pollinosis, we studied reactions to medical treatment via X-ray images of patients during the 2000 cedar pollen season. Medication was administered to 577 patients consulting facilities in 3 regions--Kyoto, Fukui and Osaka--having different pollen counts i.e., 4555/cm2 in Fukui, 801/cm2 in Kyoto and 531/cm2 in Osaka. The paranasal sinus was X-rayed by Water's method, and the degree of positivity was classified by Katagiri'shadow classification. Patients were grouped into 334 suffering extensive Fukui pollen dispersion and 243 suffering relatively limited Kyoto and Osaka pollen dispersion. At 3-4 weeks after pollen dispersion, contrast shadow positivity was 22.2%, with no difference before pollen dispersion (22.2%) in Kyoto and Osaka. In Fukui, positivity was 39.7%, a clear increase over pre pollen dispersion (19.2%). In the initial treatment group, positivity was 25.8% in Fukui and 28.6% in Kyoto and Osaka. Our results suggest that the incidence of sinusitis in patients with Japanese cedar pollinosis tended to increase with exposure to extensive pollen dispersion and to be suppressed by initial treatment.

Prevalence of Japanese cedar pollinosis among schoolchildren in Japan.

BACKGROUND: Japanese cedar pollinosis is an important allergic rhinoconjunctivitis in Japan in spring. We investigated the relationship between the amount of pollen in the air and the prevalence of the disease and sensitization to Japanese cedar pollen in this ecological study. METHODS: The IgE antibody to Japanese cedar pollen (JCP-IgE) was determined in human serum and rhinoconjunctival symptoms were surveyed in 407-510 children in May or June every year from 1995 to 2001. Japanese cedar pollinosis was defined as being JCP-IgE >or=1.5 IU/ml and having any rhinoconjunctival symptom lasting 3 weeks or longer in March or April. RESULTS: Prevalence rates of Japanese cedar pollinosis were 13.8-22.9%. Prevalence rates of being JCP-IgE >or=1.5 IU/ml were 39.0-50.1%, and those of being JCP-IgE >or=15.01 IU/ml were 11.4-23.2%. All prevalence rates were significantly related to the amount of pollen in the air. The proportion of subjects with rhinoconjunctival symptoms was relatively constant in each stratum of low JCP-IgE levels (<0.35, 1.50-2.99, 3.0-14.9 IU/ml). CONCLUSION: High exposure to Japanese cedar pollen was associated with higher levels of JCP-IgE antibody and a high prevalence of Japanese cedar pollinosis. The relationship between the level of JCP-IgE and the proportion of subjects with symptoms was relatively constant.