AAIQ   The Association of Allergists and Immunologists of Québec

Mold allergy

Molds may be found both indoors and outdoors. Outside, they are typically present from spring to autumn (from the thaw to the first frost). An elevated mold count may also be found in certain houses or apartments. There are many species of mold, and several of these prefer an indoor environment. The presence of humidity (major water damage, water leaks) and a surface favoring their growth constitutes the two elements necessary for the growth of mold species. Molds then produce spores, which become airborne. Outside, the wind contributes to the dispersal of these spores.

Certain molds release strong odors which may be irritant in nature and cause symptoms of rhintis, even though the person affected might not actually be allergic to the mold in question.

Here are some recommenations to reduce your exposure to this type of allergen:

  • Air conditioning will limit your exposure, but you must also check that the conditioning units are themselves mold-free, since they may become contaminated.
  • Avoid working in the garden.
  • Ensure that water leaks are repaired and cleaned.
  • Control the level of humidity (45% or less).
  • Eliminate all traces of molds within the house.
  • Limit the number of plants within the house, since the potting soil may become contaminated with molds.


Simon Hotte, MD FRCPC
(translation: Andrew Moore, MD FRCPC)