Samples taken from 41 down- and feather-filled quilts showed similar results as well. Only 6 of the tested quilts were infested (mite concentrations were no hazard to health from an allergological standpoint, however), although the tests were carried out on a selection of quilts, that were particularly soiled. It was evident, that they had not been cleaned for at least 15 years, in many cases even for a much longer time.
- If the fabric of the bedding is down-proof, it represents a proper “mite barrier”. It is very tightly woven, in order to prevent the down and feathers from leaking out. Neither house-dust-mites nor the scales of human skin which the mites feed on, can enter through the shell fabric.
- In addition, the thermal conditions and the climate of down- and feather-filled bedding are highly unfavourable to mites. They depend on humidity to survive, whereas the quick creation of warmth in one’s sleep and the quick reduction of humidity when the bedding is aired make for an environment which is detrimental to mites.
(Borowski, C., Schäfer, T., Allergieprävention. Evidenzbasierte und konsentierte Leitlinie [Evidence-based and consented guideline on allergy prevention]. München 2005, S. 9 [p.9])
www.uni-duesseldorf.de/AWMF/ll/061-016.htm
In the following you will find the list of studies on house-dust-mite allergy which have been evaluated by the Allergy Prevention Action Alliance for the guideline on pages 64 to 66 (Wheeze or wheezing is the term used to describe the laboured breathing):
- Risk factor
Ponsonby, A. L./Dwyer, T./Kemp, A./Cochrane, J./Couper, D./Carmichael, A., Synthetic bedding and wheeze in childhood. Epidemiology 2003; 14: 37-44
"When synthetic pillows were used during the first month of life or when synthetic bed linen was still used at the moment when the study was carried out, seven-year-olds displayed a significantly increased risk of developing wheezing symptoms. Children who suffered from asthma and who slept on synthetic pillows at an early age displayed symptoms earlier. The transferability of the results of this birth cohort study by Ponsonby et al. could be limited by the country of Tasmania."
Zacharasiewicz, A./Zidek, T./Haidinger, G./Waldhor, T./Suess, G./Vutuc, C., Indoor factors and their association to respiratory symptoms suggestive of asthma in Austrian children aged 6-9 years. Wien Klin Wochenschr 1999; 111(21): 882-886
"A trial by Zacharasiewicz et al. also included testing concerning the use of synthetic bed linen and the consequences on 6- to 9-years-olds. This study shows that using synthetic bedding represents a significant risk factor for the development of wheezing symptoms. Patients who had been diagnosed with asthma were excluded from the testing, but people who displayed wheezing symptoms throughout the preceding 12 months might have been part of the control group and might therefore distort the effect. "
- Negative and/or protective effect
Strachan, D. P., Home environment and severe asthma in adolescence: a population based case-control study. British Medical Journal 1995; 311(7012): 1053-1056
and
Butland, B. K./Strachan, D. P./Anderson, H. R., The home environment and asthma symptoms in childhood: Two population based case-control studies 13 years apart. Thorax 1997; 52(7): 618-624
"The use of feather duvets and feather pillows or synthetic pillows, respectively, showed a protective effect on the development of wheezing symptoms in children and adolescents aged between 11 and 16 years."
-
No association and protective effect
Ponsonby, A. L., Feather bedding and house dust mite sensitization and airway desease in childhood. J Clin Epidemiol 2002; 55(6): 556-562
"Ponsonby et al. could not establish any effect for the use of feather pillows and feather duvets on the development of asthma in 8-year-old children from Tasmania. The frequency of wheezing symptoms (> 12 episodes), however, was associated inversely to feather bedding."Ponsonby, A. L./Gatenby, P./Glasgow, N./Mullins, R./Hurwitz, M./McDonald, T., The association between synthetic bedding and adverse respiratory outcomes among skinprick test positive and skin-prick negative children. Allergy 2002; 57(3): 247-253"Dividing the participants into SPT-negative and SPT-positive patient groups led to the result that SPT-negative patients did not display any association with the use of synthetic bedding. On the other hand, the use of synthetic bedding led to an increased risk of asthma and allergic rhinoconjuctivits among SPT-positive patients. In the case-control study conducted among 8- to 10-year-old children by Ponsonby et al. the group of controls was not clearly defined and the chronological factor was not discussed."Rylander, E./Pershagen, Parental smoking and other risk factors for wheezing bronchitis in children. Eur J Epidemiol 1993; 9(5): 517-526"The use of feather-/down-bed linen in the parents’ beds seemed to have a protective effect concerning the development of wheezing symptoms among the children. This was tested by Rylander et al. among children aged > 18 months. Younger children did not display this effect. A distortion of the results cannot be excluded, as the tested patients were hospital cases."
-
Protective effect
Nafstad, P./Nystad, W./Jaakkola, J. J. K., The use of a feather quilt, childhood asthma and allergic rhinitis: A prospective cohort study. Clin Exp Allergy 2002; 32(8): 1150-1154"A birth cohort study carried out by Nafstad et al. showed a protective effect when the feather bedding was used until the age of 24 months. The longer the feather bedding was used, the lower the risk to contract asthma at the age of 4. One could raise the question, whether the time frame for the diagnosis was adequate, as asthmatic symptoms during childhood may disappear by themselves."Moscato, G./Perfetti, L./Galdi, E./Pozzi, V./Minoia, C., Levels of house-dust-mite allergen in homes of nonallergic people in Pavia, Italy. Allergy 2000; 55:873-878
"Mattresses display a significantly higher content of Der p 1, when synthetic pillows are being used instead of pillows made of wool or feathers."Hallam, C./Custovic, A./Simpson, B./Houghton, N./Simpson, A./Woodcock, A., Mite allergens in feather and synthetic pillows. Allergy 1999; 54: 401-408
"By replacing synthetic pillows with pillows made of different materials or by encasing pillows, the prevalence or the severity of asthma symptoms could be reduced."On the basis of the evaluated studies the Allergy Prevention Action Alliance stated the following:
"In conclusion, the so called encasing [the protection of the bedding with mite-proof covers] is an effective method to reduce the concentrations of house-dust-mites. Furthermore, regularly changing and washing the bed linen at a temperature of at least 55 oC/131 oF as well as the use of feather bedding show a rather protective effect on the development of asthma and allergy symptoms.“(Borowski, C., Schäfer, T., Allergieprävention. Evidenzbasierte und konsentierte Leitlinie [Evidence-based and consented guideline on allergy prevention]. München 2005, S. 66 [p.66])
The Medical Association of German Allergologists (Ärzteverband Deutscher Allergologen e. V.) applies the results of the evaluated trials not only to prevention. Referring to the guideline on allergy prevention the Association even issues the above mentioned recommendation for house-dust-mite sufferers, that – contrary to the recommendations given so far – synthetic bedding is not beneficial, using natural materials such as down and feathers would be better.