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[Nationwide intradermal test with chironomid midge extract in asthmatic children in Japan]
Y Adachi1, G Murakami, Y Adachi
1Department of Pediatrics, Toyama Medical and Pharmaceutical University.
Insights
Chironomus plumosus (CP) is a common inhalant allergen in Japan. A study found that 27.9% of asthmatic children tested positive for CP allergy, with higher rates in rural areas.
Area of Science:
- Environmental Allergens
- Pediatric Allergy
- Immunology
Context:
- Chironomidae midges are increasingly recognized as significant inhalant allergens in Japan.
- Asthma prevalence in children necessitates understanding environmental triggers.
- Geographic variations in allergen exposure can influence allergic sensitization.
Purpose:
- To investigate the prevalence of sensitization to Chironomus plumosus (CP) in Japanese asthmatic children.
- To explore correlations between CP allergy and other common allergens.
- To assess the relationship between CP allergy and asthma exacerbations, age, and living environment.
Summary:
- Intradermal testing with CP extract on 718 asthmatic children (6-15 years) revealed a 27.9% positive rate, increasing with age.
- CP allergy showed no significant correlation with RAST, mite, HD, or silk allergy tests, but a correlation with silk prick tests (p<0.01).
- CP-allergic asthmatics experienced more summer attacks (p<0.01), and higher positive rates were observed in children near agricultural fields (31.3%) versus urban areas (23.8%, p<0.05).
Impact:
- Identifies Chironomus plumosus as a key allergen contributing to childhood asthma in Japan.
- Highlights the importance of environmental factors, particularly rural proximity, in CP sensitization.
- Suggests potential for targeted allergen avoidance strategies for asthmatic children in affected regions.
Abstract:
Chironomidea (Insecta) is recently considered one of the most common inhalant antigen in Japan. Intradermal tests with Chironomus plumosus (CP) extract were undertaken on seven hundred and eighteen asthmatic children aged from 6 to 15 years in 10 areas (11 medical institutions) in Japan. The number of cases who showed positive intradermal tests with CP extract was 200 (27.9%) and the positive rate increased in proportion to their age (p less than 0.005). In each of the 11 medical institutions the positive rates ranged from 12.6% in Akita to 45.5% in Okinawa. There were no significant correlations between the results of the intradermal test with CP and those of RAST, prick test and intradermal test with mite, HD and silk, whereas correlation was noted in the prick test with silk (p less than 0.01). The CP positive asthmatics had significantly more attacks than the CP negative ones in the summer (p less than 0.01). The positive rate of asthmatics living near paddy or farm fields was significantly higher than that of those in urban residential areas (31.3% vs 23.8%, p less than 0.05). Chironomid midge is one of the most common and important allergen in Japan.