House Dust Avoidance during Pregnancy and Subsequent Infant Development: The Japan Environment and Children’s Study

House dust, well known for causing allergy, contains chemicals that are harmful to fetal neurodevelopment. However, whether countermeasures for house dust allergy, such as frequent use of vacuum cleaners, frequent airing of futons, and the usage of anti-mite covers during pregnancy, are related to subsequent reduced risk of infant developmental delay remains unknown. Therefore, we examined this association by analyzing 81,106 mother-infant pairs who participated in a nationwide birth cohort in Japan. Infant developmental delays at 6 and 12 months postpartum were assessed using the Ages and Stages Questionnaire, Third Edition. A generalized linear model analysis was used to derive adjusted odds ratios (AORs) with the lowest care frequency as reference, while controlling 22 covariates. Our analysis showed that the above-mentioned cleaning measures were overall associated with a reduced risk of developmental delays, both at 6 and 12 months postpartum (AOR varied from 0.73 to 0.95, median: 0.84). Additionally, risks tended to decrease with an increase in the cleaning frequency. In conclusion, a negative dose-response association existed between these measures during pregnancy and infant developmental delay. Our results identify a potential role of frequent vacuum cleaning, airing bedding, and usage of anti-mite bedding covers in promoting intact infant development.

Nasal Function following Carbon Dioxide Laser Turbinate Surgery for Allergy

A carbon dioxide laser (CO2 laser) was used to treat the hypertrophic inferior turbinates of 121 patients with nasal symptoms related to house dust allergy. Follow-up ranged from 6 to 48 months (mean follow-up period: 17.8 months). Treatment involved 10–14 watts of a defocused pulse beam of a CO2 laser fitted with special handpieces. Subjectively, 111 of the 121 patients (91.7%) reported a reduction in nasal stuffiness, 76 of the 112 patients (67.9%) had reduction in rhinorrhea, and 63 of the 96 patients (65.7%) had decrease in sneezing. Nasal airflow resistances were confirmed to have decreased in 82 patients using rhinomanometry. Nasal provocation reactions by a house dust disk, which were investigated in 10 patients, showed a tendency to reduce from 1 to 11 months after laser treatment. Nasal mucociliary transports, which were followed by the saccharin test in 50 patients, recovered 1–1.5 months after the laser surgery. To study mucosal structure after laser irradiation, the inferior turbinates of five patients were examined under a light microscope. The ciliated epithelium was shown to have recovered on light microscopic examination, whereas the number of goblet cells decreased. A net of new collagen fibers was observed in the superficial submucosa a few months after treatment. The quantity of submucosal glands was reduced in the treated portion. Such findings suggested that CO2 laser turbinate surgery may be effective in relieving the nasal symptoms associated with allergy.