Free standing buildings, the presence of flowers, employed house-wives, typical beds (with mattresses), carpeted floors, higher level (floors I-IX), PVC windows, pillows, higher cleaning frequency (times per week) and signs of dampness were significantly associated with rhinitis, atopic dermatitis, higher IgE levels both for D. pteronyssinus and D. farinae, and reactivity on other allergens (other than domestic mites) (p ≤ 0.01 in all cases) whereas their influence on the severity of asthma was statistically nonsignificant (p > 0.1 in all cases). The gene discussed is IGHE; the disease is asthma.