However there are airborne allergens such as pollens and molds and these can cause symptoms such as runny noses, itchy or wateryeyes and sometimes swelling, itchiness and sneezing.
Pollen allergies usually disappear once the pollen-producing season is over, if these symptoms are all year round, then it is more likely to be airborne dust or mold.
Mold is found in any damp area in the house and common is bathrooms and cellars. It is easy to spot black mold, there are other forms which are less visible.
Mold can also be ingested from certain foods such as dried nuts and seeds, dried fruit, green salads and some moldy cheeses and these need to be avoided by mold sensitive children.
Dust allergies cause symptoms similar to pollen and one piece of dust can contain pet dander, dead dust mites and mold spores, in addition to dead skin. Keep the house as clear as possible of dust collecting items such as carpets, curtains and soft furnishings.
Use of A HEPA filter, frequent vacuuming and regular hot washing of bedding will help remove the dust.