Note to People with Allergies: Pollen Peaks at Different Times

Seasonal grass allergy patients may need to correspond time spent outdoors with changing pollen counts

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) People with allergies know that the severity of their symptoms can change during the day, and based on new research, there may be a pattern to when allergies will be at their worst.

A team in Denmark has found that instead of avoiding all outdoor activity, there may be specific times allergy patients should stay indoors. Those specific times changed depending on the part of allergy season.

"Talk to a medical professional about managing seasonal allergies."

Dr. Robert Peel, of the Department of Environmental Science at Aarhus University in Denmark, led this research.

Dr. Peel and team conducted a three-year study of grass pollen counts in the Danish coastal city of Aarhus using specialized equipment mounted on rooftops. They found three distinct spikes over the two-month pollen season.

These researchers found distinct peaks during the first, middle and last parts of allergy season, which in Aarhus runs roughly from late May to late July or early August.

The early season displayed twin peaks in the morning and the evening, suggesting that people with allergies should avoid outdoor activity during those times.

The mid-season pollen count peaked once in the evening, and the late season peak came in the late morning and into the early afternoon.

“People should avoid being outdoors during the peak hours,” Dr. Peel said in a press statement.

Pollen is released by flowering plants during the reproductive cycle and is a common allergen. For those with pollen allergies, exposure to pollen can cause headache, sinus pressure and runny nose, among other symptoms of varying severity.

Dr. Peel and colleagues concluded that the change in peak times “most likely reflects a succession of grasses flowering and dominating pollen emissions as the season progresses.”

In turn, the exact time of year grasses flower and release pollen is driven primarily by weather patterns.

Dr. Peel said the primary way to avoid pollen-related allergies is to stay inside during peak times. To work with the change in peak hours, keep up with local pollen count forecasts.

Another variable is the species of grasses in a particular area. Dr. Peel’s study in Aarhus included common-name species such as meadow foxtail, orchard grass, tall fescue and tufted grass.

This research was published in the peer-reviewed journal Biogeosciences

Funding was provided by the Aarhus University Research Foundation and the Danish Asthma Allergy Association.

Review Date: 
May 29, 2014
Last Updated:
May 29, 2014