The relationships among Dermatophagoides pteronyssinus exposure, exhaled nitric oxide, and exhaled breath condensate pH levels in atopic asthmatic children.

This study examined seasonal changes in indoor Dermatophagoides pteronyssinus 1 (Der p 1)/Blattella germanica 1 (Bla g 1) antigen concentrations in the homes of atopic asthmatic and atopic nonasthmatic children. Possible associations between environmental allergen exposure and levels of exhaled breath indices were also evaluated.A total of 38 atopic children were recruited for this cross-sectional study: 22 were asthmatic and 16 were nonasthmatic. Home visits were conducted for indoor air and dust sampling each season. Exhaled nitric oxide (eNO)/spirometric measurements were taken and exhaled breath condensate (EBC) was collected after sampling of the domestic environment.The highest Der p 1 concentrations were on the top of mattresses in the homes of recruited children. The floors of kitchens and living rooms had the highest Bla g 1 concentrations in the homes of atopic asthmatic children. A positive correlation was found between Der p 1 exposure of mattress, bedroom floor, and living room floor and eNO levels in the atopic asthmatic children. The Der p 1 concentrations on the surfaces of mattress and bedroom floor were positively related to high eNO levels in the atopic asthmatic children after adjusting for season. No association was found between Der p 1 exposure and EBC pH values in the recruited children.A positive correlation was found between Der p 1 exposure and high eNO levels in atopic asthmatic children, especially in Der p 1 exposure of mattress and bedroom floor.