Avoidance measures
Avoidance of relevant allergens/irritants is an important
component of asthma management. Patients allergic to
house dust mites should be instructed to use allergenimpermeable
covers for bedding and to keep the relative
humidity in the home below 50% (to inhibit mite
growth). Pollen exposure can be reduced by keeping
windows closed, using an air conditioner, and limiting
the amount of time spent outdoors during peak pollen
seasons. For patients allergic to animal dander, removal
of the animal from the home is recommended and
usually results in a significant reduction in symptoms
within 4-6 months. However, compliance with this
recommendation is poor and, therefore, the use of highefficiency
particulate air (HEPA) filters and restricting
the animal from the bedroom or to the outdoors may
be needed to attempt to decrease allergen levels. Measures
for reducing exposure to mould allergens include
cleaning with fungicides, de-humidification to less than
50%, and HEPA filtration. Cigarette smoking and exposure
to second-hand tobacco smoke should also be
avoided [7].