House dust mites are tiny insects, about 0.03mm long, look scary under a microscope but too small to be seen by us. They are definitely in our homes as house dust mites, or HDM, love room temperature (18 deg C to 26 deg C/65 to 80 deg F), humid (above 55%) homes where there are plenty of shed human skin for food. HDM feed on our dead skin, fingernails, hair, animal fur, bacteria, fungi and pollen. In your home, they are likely to be on the bed, mattress, carpets, upholstered furniture and curtains. There is no way to have zero dust mite in your home, but you can reduce their quantity by making the environment less favourable for them. It takes a lot of effort to keep the dust mites away, so we should understand a little bit more before killing ourselves with the cleaning.
How does house dust mite affect your eczema child?
First things first, get your child tested. A skin prick test will show if your child is allergic to the droppings of the house dust mite. It’s the protein in the droppings that is the allergen, and not every eczema child will be allergic to HDM (my baby Marcie isn’t) though patients with eczema could be more susceptible to dust mite allergy (taken from “Specific profiles of house dust mite sensitization in children with asthma and in children with eczema” article in Pediatric Allergy and Immunology 2010). It was also written in the same article that those with eczema by 3 months old is more likely to be sensitized to aeroallergen by 5 years old. Also, the more severe the eczema, the greater the sensitization to HDM. In the article, it is noted that the major HDM allergen for eczema patients is Der p1 of D.pteronyssinus, which is a large particle that don’t stay airborne but quickly land on surface, including on the skin. For eczema children with defective skin barrier, the allergen can penetrate the skin more easily to trigger itchiness.
How to reduce house dust mite?
If your child is tested allergic or get asthma attack from inhaling the HDM allergen, then there’s little choice but to get rid of as much dust (and the dust mite dropping trapped in the dust) as possible. Here’re a few ways to keep the dust mites away:
1. Remove carpets, thick curtains, thick mattress, upholstered furniture (think plastic, wood, leather, vinyl).
2. Get dust mite proof covers for the pillows and mattresses.
3. Wash bed sheet, pillow cases weekly at temperature of above 60 deg C (you can see my washing machine here, I steam wash everything).
4. Wipe your home with wet cloth, instead of dry dusting from one area to the air (finally, there’s some support for what I love to do, using a wet kitchen towel to clean everything).
5. If vacuuming, get a vacuum cleaner with a good filter that does not release small particle in the exhaust; I borrow my friend’s $3000 vacuum cleaner twice a year to vacuum mattress; but if your child has asthma, then the mattress needs to be vacuum weekly. (Dust mite can burrow deep into the mattress and will be hard to vacuum away if the mattress is thick.)
6. Ventilate room; this will reduce stale humid air trapped in the room, and let the sun in (think less cosy for the dust mite).
7. No soft toys; if your child absolutely can’t do without them, try freezing the soft toys in plastic bag for 24 hours in the freezer to kill the dust mite, followed by washing away the dead mites and droppings in the washing machine.
8. Reduce humidity, but too dry environment is bad for eczema, read this post on humidifier and air-con.
9. Reduce ornaments, dried flowers, books, textured wallpapers; the less surface for dust to land on, the better.
Save your money on these:
1. Don’t buy mite killing sprays which may be an irritant; likewise, for ionizers.
2. Don’t buy air filters because the air filter may stir up air, making it longer for the dust to settle (which increases risk for asthma children as the HDM allergen stays airborne). Or air filter may end up filtering only the air near to the filter.