The House Dust Mite


The House Dust Mite (Dermatophagoides Pteronyssinus = Skin eating feather lover!) is the most potent single cause of asthma with about 85% of asthmatics showing evidence of “allergy”. In fact it is the faecal droppings produced by the mite which are the real bad actors; they are dry, very irritant and extremely tiny and able to float on the air and into the small airways where they trigger an allergic reaction. Since you have about 2000 of these mites on your pillow alone, each producing about 20 faecal droppings each night, you can imagine the size of the problem!


Its numbers have increased enormously over recent years (and so has the problem of asthma) because it thrives in warm moist atmospheres with an ideal temperature of 25˚C (77˚F) and relative humidity of 75 – 80% (i.e. very humid!). It makes sense to try to reduce the numbers of this bug – especially to prevent young children with an allergic tendency from becoming sensitive; in established asthma, it may take many months or even years to reap the benefits of mite elimination.


Here are some principles


1. Take away its hiding places! (especially in the bedroom)


a.     Cover your bedding with anti-mite barrier covers (available from Boots or other major Chemist).

b.    Remove soft toys from children’s beds; wash them regularly and deep-freeze them occasionally to kill off the mites.

c.     Avoid dust by damp dusting and vacuum cleaning with a high-efficiency vacuum cleaner.

d.    Put clothes away in cupboards and avoid untidiness, clutter and dust.

e.    Avoid soft furnishings where possible – linoleum, tile or bare wood is better than carpet; plastic or leather is better than fabric upholstering.

f.     Replace woollen blankets with cotton or synthetic materials.


2. Reduce its numbers!


a. Hot wash bed linen (60˚C) at least once/week.

b. Put your blankets and mattresses out in the sun in summer; sunlight kills the mite.

c. Air your mattress thoroughly at least once per month


3. Spoil its Habitat!


a.     Air and Ventilate the house by opening windows

b.    Reduce moisture in the air with an extractor fan.

c.     Especially when cooking or laundry, ensure good ventilation.

d.    Remove any sources of damp, rising damp or water leaks in the home.

e.    Cooler homes are less mite-friendly!


Any tips on House Dust Mite avoidance that can be added to these instructions would be much appreciated as would “best-buy” purchases you may encounter.



Dr. Bernard Shevlin