Bedding is an important habitat for house dust mites (HDM), and indeed acts as a sink for mite allergens. Dust from the bed often has higher allergen concentrations than other parts of the house. They are also the only site where allergen levels are associated with severity of asthma. Beds have for a long time been suggested as the most important source of house dust mite allergen exposure for children, due to the fact that infants and children alike spend more than half their time in close contact with bedding.
HDMs feed on human skin scale in locations where it collects. We shed dead skin at a daily rate of 0.5 to 1.0g per person; this is more than enough for several thousand dust mites as they can survive for months on just 0.25g of dead skin. As such, the more children spend in bed, the more likely they are to develop sensitisation to dust mites, which could lead to the development of asthma. As the start of the school year draws ever closer, the importance of proper care and consideration of bedding for children in particular cannot be over-emphasized as the result of negligence could adversely affect their health and consequently their overall performance.
Tips for keeping your child’s bedding free of mites
Important tips to consider for successful reduction of the amount of house dust mites and their allergens in your child’s bed.
1. Mattresses, duvets and pillows should be covered with dust mite proof covers. Use bedding that can be washed often, cotton sheets, washable bottom sheets and synthetic blankets or duvets.
2. Do not use woolen blankets or quilts, if however you have to use woolen blankets or quilts, wash them at least every 2 months to remove allergens. Dry cleaning of these and other bedding will kill the mites but does not remove the allergens.
3. Even if you use dust mite proof covers, you should wash all sheets, pillowcases, quilt or doona covers and cotton blankets once a week to remove both mites and allergens.
4. Wash bedding in hot water (55°C or more), sustained for at least 12 min (or above 60°C for 8 min). This is sufficient to kill >80% of dust mites. If you can only wash in cooler water, use a product containing essential oils, such as tea tree or eucalyptus oil.
5. Leave the child’s bed unmade during the day so as to release moisture from the mattress. This causes the mites to dehydrate and eventually die.
6. Keep the house and the child’s room well ventilated, cool and dry. Dust mites hate dry and cold air, so try to air the house everyday. If the lower edge of the window is moist when you wake up in the morning, there is too much humidity in the air. Dehumidifiers are excellent at reducing the level of humidity indoors.
Useful links
National Asthma Council Australia – Why is bedding important?
http://www.nationalasthma.org.au/html/management/infopapers/consumer/6002.asp
National Asthma Council Australia – Current suggestions for the bedding of infants.
http://www.nationalasthma.org.au/html/management/infopapers/health_professionals/6002.asp#bed
BBC News – Your bedding could make you ill
http://news.bbc.co.uk/1/hi/health/741908.stm
References
1. Vanlaar CH, Peat JK, Marks GB, Rimmer J, Tovey ER. Domestic control of house dust allergen in children’s beds. J Allergy Clin Immunol 2000; 105(6):1130-1133.
2. Mihrshahi S et al. Effectiveness of an intervention to reduce house dust mite allergen levels in children’s beds. Allergy 2003; 58: 784-789.
3. Lee IS, Moon JS, Yoo YS. Effectiveness of bedding control instruction for patients with respiratory allergies: A randomized controlled trial. Int J Nurs Stud 2006; doi: 10.1016/j.ijnurstu.2006.08.009.
4. Causer SM, Botica KJ, Shorter CL. Removal of house-dust mites and Der p 1 during laundering of bedding. Allergy 2003; 58: 531-541.
