house dust mite also called as HDM by some allergists is one of
the most common allergen that triggers
asthma attack in
typical dust mite measures 420 µm in length and 250 to 350 µm in
diameter. It is possible to see house dust mite by a magnifying
glass in a well lit place and on a black background.
dust mite is globular in shape, creamy white in color with
striated cuticle. Two main species are American house dust mite
(Dermatophagoides farinae) and European house dust mite
(Dermatophagoides pteronyssinus). Both species are distributed
worldwide and are not necessary confined to Europe or North
dust mite feeds on the organic detritus such as flacks of dead
human skin, and flourishes in a humid environment of the homes.
Dust mites can be transported airborne by minor air currents
generated by usual household activity.
from asthma house dust mites are also responsible for:
Watery and itchy eyes and
Important measures that can be
taken to control house dust mites are:
Mattress and pillows should be encased in special dust proof
2. Pillows should be washed every week in hot water. Water must
be hotter than 130 °F to kill the mites.
3. Sheets and blankets of your bed should be washed each week in
hot water (>130 °F).
4. Carpets should be removed from bedroom and preferably from
the house if allergy symptoms are severe.
5. Sleeping or lying on upholstered furniture to be avoided.
6. Carpets that are laid on the concrete should be removed.
7. Indoor humidity should be reduced to less than 50 %.
8. Stuffed toys must be removed from bed of children who are
allergic to house dust mites. These toys should be washed weekly
in hot water.
9. Vacuuming is helpful in removing mite allergens from the
carpets but is not able to remove live mites.
10. Chemical agents are available for killing mites and
denaturing mite antigens. However the effects are not dramatic
and are not maintained for long periods. Therefore uses of these
agents are not recommended routinely (Woodfolk et al. 1995)