Allergen Update

Sherbrooke, Quebec

Predominant pollen:

The tree pollen seasons can fluctuate from year to year by as much as two to four weeks at this site due to the effect of weather. The pollen seasons described here try to cover the time when each can occur.

Acer sp.- The maples can have a short early season from mid to early April. The main season can start from early to mid-April and end mid to late May. Some very high counts are observed and some species are known to cause allergic reactions.

Alnus sp.- The alder season can start mid-March to early April and end early to late June. Moderate and high counts can occur. Alders are considered important allergens.

Betula sp.- The birch season can start from mid-April to early May and end early to late June. Very high counts are observed and they are considered important allergens.

Birch look-a-likes sp.- Low to moderate counts are possible. The season can start late April to early May and ends late May. Some species can cause allergic reactions.

Cupressaceae family- The cedars, junipers and yews season starts from early to late March and ends late May to early June. Very high counts can be observed but most species in Canada are not considered allergenic.

Tsuga sp.- the hemlock season lasts approximately one to three weeks and varies a great deal from year to year. The season can start from the second week of May to early June and end the third week of May to the second week of June. Some years moderate and high counts are possible.

Larix sp.- The larch season can vary a great deal from year to year. The season can produce moderate counts or very sporadic low counts. The season can start mid to late April and end late April to early May.

Pinaceae family- High counts are observed throughout the season. The pollen season can start from late April to the second week of May and ends early to late July. This group of trees are important to those individuals sensitized.

Populus sp.- Poplar, cottonwood and aspen produce very high counts which can cause allergic reactions. The season can start from the third week of March to the third week of April and end early to mid-May. The season can start early in warm years like 2010 and 2012.

Quercus sp.- The oak season can start from mid-April to early May and end the third week of May to early June. The counts can get high and some species are known to cause allergic reactions.

Ulmus sp.- The elm are highly allergenic. An early sporadic season, with low counts, can ocur the third week of May to early April. The main season, which usually has moderate counts, can start the second to third week of April and end late April to early May.

Fraxinus sp.- The ash season can start from mid-April to early May and end mid-May to early June. Some very high counts can be observed and this could cause allergic reactions in sensitized individuals.

Fagus sp.- The beech season varies a great deal from year to year. This is partly due to cyclical patterns and weather. The season can start from early to mid-May and end late May to the second week of June. Most of the counts are low but in rare years moderate counts are observed.

Salix sp.- The willow season lasts about four weeks. The season can start mid to late April and end mid to late May. Occasional moderate counts are possible which may cause allergic reactions in sensitized individuals.

Gramineae family- The grass season can start early to mid-May and end early October. Moderate and the occasional high counts are observed from early June to late July.

Ambrosia sp.- The ragweed season can begin from mid-July to early August and end early to mid-October or with a heavy frost. Moderate counts can be observed from the second week of August to early September.

Artemisia sp.- The sagebrushes and wormwoods produce mostly low and the occasional moderate count from the second week of July to early October. May be a source of allergenicity.

Urticaceae sp.- The nettles and the parietaria produce low and moderate counts. The season can start mid to late June and end mid to late September. They are considered important allergens due to their small size.

Plantago sp.- The plantains produce mostly low and occasional moderate counts. The season can start late May to early June and late September. They can cause allergic reactions even in low numbers to sensitized individuals.

Predominant Spores:

Diatrypaceae sp.- The counts are very sporadic and vary throughout the whole counting season. Very high counts are observed from March to late October. They are not known to cause allergic reactions.

Caloplaca sp.- Moderate and high counts are observed from mid-May to late September. Season is very sporadic. May not be an important cause in allergic reactions.

Leptosphaeria sp. & Leptosphaeria look-alikes- These two are grouped together since they are in the same class of fungi and are similar microscopically. The season is from mid-April to mid-October with great fluctuations in counts from day to day. This is probably due to the effect of weather. Some high counts are observed for both groups.

Erysiphe (Oospora) sp.- Powdery mildew - The season is from mid-April to mid-October. Counts are in the low to very high ranges. May not be an important allergen.

Boletus sp.- Season is from June to the end of October. Late July to October is when the highest counts are observed.

Coprinus sp.- High counts are observed and the season is from May to late fall. May be an important allergen.

Ganoderma sp.- Very high counts are observed from June to mid-October. May be an important allergen.

Ustilaginales sp.- The smuts produce low to high counts from May to mid-October. Allergenicity is unknown.

Uredinales sp.- The rusts produce low to high counts from May to mid-October. Allergenic properties are not well understood.

Penicillium sp. & Aspergillus sp.- Significant counts occur throughout the whole counting season with high counts occurring from March to late fall.

Alternaria sp.- Most of the significant counts are found from June to mid-October and are generally in the low to high ranges. May not cause disease except in highly sensitized individuals.

Cladosporium sp.- Found throughout the whole counting season. High counts are observed in March and April with very high counts starting June to late fall.

Botrytis sp.- Counts are in the low to moderate ranges from April to early October.

Helicomyces sp.- The season is very sporadic and low to high counts are observed from April to mid-October.

Fusarium sp.- Sporadic counts are observed throughout the whole collecting season. Moderate to high counts are observed from May to early October.

Pithomyces sp.- Low to moderate counts are observed from June to early October.

Epicoccum sp.- Low to high counts occur from June to mid-October.

Polythrincium sp.- Very high counts are observed from June to the end of September.

Myxomycetes- Low and moderate counts are observed from May to mid-October.

Last Updated: 3 March 2015

The information presented here is designed to inform, not replace, the relationship that exists between a patient and a medical professional.

About | Legal & Privacy | Contact