NEW MATTRESSES - HOW FAST DO THEY BECOME A SIGNIFICANT SOURCE OF EXPOSURE TO HOUSE-DUST MITE ALLERGENS

Background Sensitization and exposure to mite allergens is a major ris k factor for asthma. Little is known about the rate of build-up of all ergens in the mite micro-habitats. Objectives To investigate the rate of increase in mite allergen levels in new mattresses. Methods Der p 1 was measured in the dust samples collected from six identical new sin gle mattresses over a period of 2 years. Results Der p 1 increased sig nificantly at 4 months as compared with baseline level (P < 0.01), but no difference was found between the concentrations at 4, 8, 12 and 24 months. There was a significant correlation between Der p 1 concentra tion in mattresses at 4, 8, 12 and 24 months and Der p 1 levels in the bedroom carpet at the beginning of the study. Conclusions New mattres ses can become a significant source of exposure to mite allergens afte r a short period of time (< 4 months). There is little justification f or advising mite sensitive patients to replace their mattresses as a p art of avoidance regime.